CVE-2023-23376
published 2023-02-14CVE-2023-23376: Windows Common Log File System Driver Elevation of Privilege Vulnerability
PriorityP186high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITWRansomware
CISA Known Exploited Vulnerabilitydue 2023-03-07
Exploited in the wild
EPSS
10.85%
95.4th percentile
Windows Common Log File System Driver Elevation of Privilege Vulnerability
Affected
44 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_10_1507 | < 10.0.10240.19747 | 10.0.10240.19747 |
| microsoft | windows_10_1607 | < 10.0.14393.5717 | 10.0.14393.5717 |
| microsoft | windows_10_1809 | < 10.0.17763.4010 | 10.0.17763.4010 |
| microsoft | windows_10_20h2 | < 10.0.19042.2604 | 10.0.19042.2604 |
| microsoft | windows_10_21h2 | < 10.0.19044.2604 | 10.0.19044.2604 |
| microsoft | windows_10_22h2 | < 10.0.19045.2604 | 10.0.19045.2604 |
| microsoft | windows_10_version_1507 | >= 10.0.10240.0 < 10.0.10240.19747 | 10.0.10240.19747 |
| microsoft | windows_10_version_1607 | >= 10.0.14393.0 < 10.0.14393.5717 | 10.0.14393.5717 |
| microsoft | windows_10_version_1809 | >= 10.0.0 < 10.0.17763.4010 | 10.0.17763.4010 |
| microsoft | windows_10_version_1809 | >= 10.0.17763.0 < 10.0.17763.4010 | 10.0.17763.4010 |
| microsoft | windows_10_version_20h2 | >= 10.0.0 < 10.0.19042.2604 | 10.0.19042.2604 |
| microsoft | windows_10_version_21h2 | >= 10.0.19043.0 < 10.0.19044.2604 | 10.0.19044.2604 |
| microsoft | windows_10_version_22h2 | >= 10.0.19045.0 < 10.0.19045.2604 | 10.0.19045.2604 |
| microsoft | windows_11_21h2 | < 10.0.22000.1574 | 10.0.22000.1574 |
| microsoft | windows_11_22h2 | < 10.0.22621.1265 | 10.0.22621.1265 |
| microsoft | windows_11_version_21h2 | >= 10.0.0 < 10.0.22621.1574 | 10.0.22621.1574 |
| microsoft | windows_11_version_22h2 | >= 10.0.22621.0 < 10.0.22621.1265 | 10.0.22621.1265 |
| microsoft | windows_server_2008 | — | — |
| microsoft | windows_server_2008_r2_service_pack_1 | >= 6.1.7601.0 < 6.1.7601.26366 | 6.1.7601.26366 |
| microsoft | windows_server_2008_service_pack_2 | >= 6.0.6003.0 < 6.0.6003.21915 | 6.0.6003.21915 |
| microsoft | windows_server_2012 | — | — |
| microsoft | windows_server_2012 | >= 6.2.9200.0 < 6.2.9200.24116 | 6.2.9200.24116 |
| microsoft | windows_server_2012_r2 | >= 6.3.9600.0 < 6.3.9600.20821 | 6.3.9600.20821 |
| microsoft | windows_server_2016 | < 10.0.14393.5717 | 10.0.14393.5717 |
| microsoft | windows_server_2016 | >= 10.0.14393.0 < 10.0.14393.5717 | 10.0.14393.5717 |
Detection & IOCsextracted from sources · hover to see the quote
- →CVE-2023-23376 is one of at least five CLFS EoP exploits attributed to the same exploit author, all sharing common debug strings and code similarities; cluster also includes CVE-2022-24521, CVE-2022-37969, and CVE-2023-28252 ↗
- →The CLFS exploit cluster (including CVE-2023-23376) uses the NtQuerySystemInformation API with the SystemExtendedHandleInformation (0x40) class to leak the KTHREAD structure address for the current thread — monitor for Medium IL processes calling NtQuerySystemInformation with class 0x40 ↗
- →The CLFS exploit cluster (including CVE-2023-23376) uses the PreviousMode technique: it decrements the PreviousMode field in the KTHREAD structure from 1 to 0, then abuses NtReadVirtualMemory/NtWriteVirtualMemory to overwrite the process token and gain SYSTEM privileges ↗
- →Exploits in this CLFS cluster (including CVE-2023-23376) operate by creating and patching a BLF (base log file) on disk before triggering the vulnerability — detection opportunity: monitor for CreateLogFile / AddLogContainer API calls followed by direct binary patching of .blf files from non-logging processes ↗
- ·Talos noted that new Snort rules were released to detect exploitation attempts for CVE-2023-23376 and the other February 2023 Patch Tuesday zero-days; customers should update SRU for Cisco Secure Firewall or download the latest rule pack from Snort.org, but specific rule numbers were not published in the source ↗
- ·The detailed technical write-up for CVE-2023-23376 specifically (Exploit #4) is in Part 5 of the Securelist series; the sources provided do not include that part's full technical content, so exact BLF patch offsets and field names for CVE-2023-23376 are not available from the provided documents ↗
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vulncheck7.8HIGH
cisa7.8HIGH
vendor_msrc7.8HIGH
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Microsoft
Windows Common Log File System Driver Elevation of Privilege Vulnerability
vendor_msrc·2023-02-14·CVSS 7.8
CVE-2023-23376 [HIGH] CWE-122 Windows Common Log File System Driver Elevation of Privilege Vulnerability
Windows Common Log File System Driver Elevation of Privilege Vulnerability
FAQ: What privileges could be gained by an attacker who successfully exploited this vulnerability?
An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.
Windows Common Log File System Driver: Windows Common Log File System Driver
Microsoft: Microsoft
Customer Action Required: Yes
Impact: Elevation of Privilege
Exploit Status: Publicly Disclosed:No;Exploited:Yes;Latest Software Release:Exploitation Detected;DOS:N/A
Reference: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022840
Reference: https://support.microsoft.com/help/5022840
Reference: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022842
Reference: https://support.microsoft.com/help/502
CISA
Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
cisa·2023-02-14·CVSS 7.8
CVE-2023-23376 [HIGH] CWE-122 Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
Vulnerability: Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
Affected: Microsoft Windows
Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.
Required Action: Apply updates per vendor instructions.
Notes: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-23376; https://nvd.nist.gov/vuln/detail/CVE-2023-23376
Remediation Due Date: 2023-03-07
GHSA
GHSA-j6mx-66rf-6rxq: Windows Common Log File System Driver Elevation of Privilege Vulnerability
ghsa_unreviewed·2023-02-14
CVE-2023-23376 [HIGH] CWE-122 GHSA-j6mx-66rf-6rxq: Windows Common Log File System Driver Elevation of Privilege Vulnerability
Windows Common Log File System Driver Elevation of Privilege Vulnerability
VulnCheck
Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
vulncheck·2023·CVSS 7.8
CVE-2023-23376 [HIGH] CWE-122 Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.
Affected: Microsoft Windows
Required Action: Apply updates per vendor instructions.
Known Ransomware Campaign Use: Known
Exploitation References: https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2023-Feb; https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit; https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json; https://securelist.com/windows-clfs-exploits-ransomware-cve-2023-23376/111593/; https://securelist.com/windows-clfs-exploits-ransomware/111560/; https://ti.qianxin.com/uploads/2024/02/02/dcc93e586f
Project0
Project Zero RCA: CVE-2023-28252: Windows Common Log File System Driver Elevation of Privilege Vulnerability
project_zero·CVSS 7.8
CVE-2023-28252 [HIGH] Project Zero RCA: CVE-2023-28252: Windows Common Log File System Driver Elevation of Privilege Vulnerability
# CVE-2023-28252: Windows Common Log File System Driver Elevation of Privilege Vulnerability
*Genwei Jiang, FLARE OTF*
## The Basics
**Disclosure or Patch Date:** April 11, 2023
**Product:** Windows
**Advisory:** https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-28252
**Affected Versions:** Before security updates of April 11, 2023, for Windows 10, 11 and Windows Server 2008, 2012, 2016, 2019, 2022
**First Patched Version:** Security updates of April 11, 2023, for CVE-2023-28252
**Issue/Bug Report:** MSRC-78564
**Patch CL:** N/A
**Bug-Introducing CL:** N/A
**Reporter(s):** Boris Larin (oct0xor) with Kaspersky, Genwei Jiang with FLARE OTF of Google Cloud + Mandiant, Quan Jin with DBAPPSecurity WeBin Lab
## The Code
**Proof-of-concept:** See exploit sample
**E
No detection rules found.
No public exploits indexed.
Greynoiseio
The Noise in the Silence: Unmasking CISA's Hidden KEV Ransomware Updates
blogs_greynoiseio·2026-02-02
The Noise in the Silence: Unmasking CISA's Hidden KEV Ransomware Updates
CVE Disclosure Early Warning Get an early warning when traffic spikes indicate a high likelihood of new disclosures
Compromised Asset Detection Find out immediately if an asset communicates with a malicious IP address
Vulnerability Prioritization Get real-time insight into active exploitation trends to better understand risk and severity
SOC Efficiency Filter out noisy, low priority and false-positive alerts from mass internet scanners
Incident Investigation Add context to incidents to speed the determinations of scope and timelines
Threat Hunting Quickly identify anomalous behavior and enrich your threat hunting campaigns
Why GreyNoise
CVE Disclosure Early Warning Get an early warning when traffic spikes indicate a high likelihood of new disclosures
Compromised Asset Detection Fin
Securelist
Mem3nt0 mori – The Hacking Team is back!
blogs_securelist·2025-10-27·CVSS 8.3
[HIGH] Mem3nt0 mori – The Hacking Team is back!
Table of Contents
- Attack chain
- Finding Dante
- Dante
- Conclusion
- Indicators of compromise
Authors
- Boris Larin
In March 2025, Kaspersky detected a wave of infections that occurred when users clicked on personalized phishing links sent via email. No further action was required to initiate the infection; simply visiting the malicious website using Google Chrome or another Chromium-based web browser was enough.
The malicious links were personalized and extremely short-lived to avoid detection. However, Kaspersky’s technologies successfully identified a sophisticated zero-day exploit that was used to escape Google Chrome’s sandbox. After conducting a quick analysis, we reported the vulnerability to the Google security team, who fixed it as CVE-2025-2783.
Acknowledgement for find
Tenable
Microsoft’s December 2024 Patch Tuesday Addresses 70 CVEs (CVE-2024-49138)
blogs_tenable·2024-12-10·CVSS 7.8
[HIGH] Microsoft’s December 2024 Patch Tuesday Addresses 70 CVEs (CVE-2024-49138)
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Securelist
Operation Triangulation: The last (hardware) mystery
blogs_securelist·2023-12-27·CVSS 5.5
CVE-2023-38606 [MEDIUM] Operation Triangulation: The last (hardware) mystery
Table of Contents
- Operation Triangulation’ attack chain
- The mystery and the CVE-2023-38606 vulnerability
- Technical details
- Conclusion
- Update 2024-01-09
Authors
- Boris Larin
UPD 23.04.2025: MITRE created a page for Operation Triangulation as part of its ATT&CK framework.
Today, on December 27, 2023, we (Boris Larin, Leonid Bezvershenko, and Georgy Kucherin) delivered a presentation, titled, “Operation Triangulation: What You Get When Attack iPhones of Researchers”, at the 37th Chaos Communication Congress (37C3), held at Congress Center Hamburg. The presentation summarized the results of our long-term research into Operation Triangulation, conducted with our colleagues, Igor Kuznetsov, Valentin Pashkov, and Mikhail Vinogradov.
This presentation was also the first time we h
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #1 – CVE-2022-24521)
blogs_securelist·2023-12-21·CVSS 7.8
[HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #1 – CVE-2022-24521)
Authors
Boris Larin
This is the second part of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous part first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
Part 1 – Windows CLFS and five exploits of ransomware operators
Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
Part 5 – Windows CLFS and five exploits of ransomware operators (Explo
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #3 – October 2022)
blogs_securelist·2023-12-21·CVSS 7.8
[HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #3 – October 2022)
Authors
- Boris Larin
This is part four of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
- Part 1 – Windows CLFS and five exploits of ransomware operators
- Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
- Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
- Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
- Part 5 – Windows CLFS and five exploits of ransomware operators (Ex
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #4 – CVE-2023-23376)
blogs_securelist·2023-12-21·CVSS 7.8
[HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #4 – CVE-2023-23376)
Authors
Boris Larin
This is part five of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
Part 1 – Windows CLFS and five exploits of ransomware operators
Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
Part 5 – Windows CLFS and five exploits of ransomware operators (Exploit #4
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #2 – September 2022)
blogs_securelist·2023-12-21·CVSS 7.8
[HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #2 – September 2022)
Authors
Boris Larin
This is the third part of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
Part 1 – Windows CLFS and five exploits of ransomware operators
Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
Part 5 – Windows CLFS and five exploits of ransomware operators (Explo
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #4 – CVE-2023-23376)
blogs_securelist·2023-12-21·CVSS 7.8
CVE-2023-23376 [HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #4 – CVE-2023-23376)
Authors
- Boris Larin
This is part five of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
- Part 1 – Windows CLFS and five exploits of ransomware operators
- Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
- Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
- Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
- Part 5 – Windows CLFS and five exploits of ransomware operators (Ex
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #2 – September 2022)
blogs_securelist·2023-12-21·CVSS 7.8
[HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #2 – September 2022)
Authors
- Boris Larin
This is the third part of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
- Part 1 – Windows CLFS and five exploits of ransomware operators
- Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
- Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
- Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
- Part 5 – Windows CLFS and five exploits of ransomware operator
Securelist
Windows CLFS and five exploits used by ransomware operators
blogs_securelist·2023-12-21·CVSS 7.8
CVE-2023-28252 [HIGH] Windows CLFS and five exploits used by ransomware operators
Authors
- Boris Larin
In April 2023, we published a blog post about a zero-day exploit we discovered in ransomware attacks that was patched as CVE-2023-28252 after we promptly reported it to Microsoft.
In that blog post, we mentioned that the zero-day exploit we discovered was very similar to other Microsoft Windows elevation-of-privilege (EoP) exploits that we have seen in ransomware attacks throughout the year. We found that since June 2022, attackers have used exploits for at least five different Common Log File System (CLFS) driver vulnerabilities. Four of these vulnerabilities used by the attackers (CVE-2022-24521, CVE-2022-37969, CVE-2023-23376, CVE-2023-28252) have been captured in the wild as zero-days.
Seeing a Win32k driver zero-day being used in attacks isn’t really surprisi
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #3 – October 2022)
blogs_securelist·2023-12-21·CVSS 7.8
[HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #3 – October 2022)
Authors
Boris Larin
This is part four of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
Part 1 – Windows CLFS and five exploits of ransomware operators
Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
Part 5 – Windows CLFS and five exploits of ransomware operators (Exploit #4
Securelist
Windows CLFS and five exploits used by ransomware operators
blogs_securelist·2023-12-21·CVSS 7.8
CVE-2023-28252 [HIGH] Windows CLFS and five exploits used by ransomware operators
Authors
Boris Larin
In April 2023, we published a blog post about a zero-day exploit we discovered in ransomware attacks that was patched as CVE-2023-28252 after we promptly reported it to Microsoft.
In that blog post, we mentioned that the zero-day exploit we discovered was very similar to other Microsoft Windows elevation-of-privilege (EoP) exploits that we have seen in ransomware attacks throughout the year. We found that since June 2022, attackers have used exploits for at least five different Common Log File System (CLFS) driver vulnerabilities. Four of these vulnerabilities used by the attackers ( CVE-2022-24521 , CVE-2022-37969 , CVE-2023-23376 , CVE-2023-28252 ) have been captured in the wild as zero-days.
Seeing a Win32k driver zero-day being used in attacks isn’t really surpr
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #1 – CVE-2022-24521)
blogs_securelist·2023-12-21·CVSS 7.8
CVE-2022-24521 [HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #1 – CVE-2022-24521)
Authors
- Boris Larin
This is the second part of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous part first if you haven’t already.
You can skip to the other parts using this table of contents or using the link at the end of this part.
- Part 1 – Windows CLFS and five exploits of ransomware operators
- Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
- Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
- Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
- Part 5 – Windows CLFS and five exploits of ransomware operator
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #5 – CVE-2023-28252)
blogs_securelist·2023-12-21·CVSS 7.8
CVE-2022-24521 [HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #5 – CVE-2023-28252)
Authors
Boris Larin
This is part six of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can go to other parts using this table of contents:
Part 1 – Windows CLFS and five exploits of ransomware operators
Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
Part 5 – Windows CLFS and five exploits of ransomware operators (Exploit #4 – CVE-2023-23376)
Part 6 – Windows CLFS and fiv
Securelist
Windows CLFS and five exploits used by ransomware operators (Exploit #5 – CVE-2023-28252)
blogs_securelist·2023-12-21·CVSS 7.8
CVE-2023-28252 [HIGH] Windows CLFS and five exploits used by ransomware operators (Exploit #5 – CVE-2023-28252)
Authors
- Boris Larin
This is part six of our study about the Common Log File System (CLFS) and five vulnerabilities in this Windows OS component that have been used in ransomware attacks throughout the year. Please read the previous parts first if you haven’t already.
You can go to other parts using this table of contents:
- Part 1 – Windows CLFS and five exploits of ransomware operators
- Part 2 – Windows CLFS and five exploits of ransomware operators (Exploit #1 – CVE-2022-24521)
- Part 3 – Windows CLFS and five exploits of ransomware operators (Exploit #2 – September 2022)
- Part 4 – Windows CLFS and five exploits of ransomware operators (Exploit #3 – October 2022)
- Part 5 – Windows CLFS and five exploits of ransomware operators (Exploit #4 – CVE-2023-23376)
- Part 6 – Windows CLF
Tenable
Microsoft’s September 2023 Patch Tuesday Addresses 61 CVEs (CVE-2023-36761)
blogs_tenable·2023-09-12·CVSS 6.5
[MEDIUM] Microsoft’s September 2023 Patch Tuesday Addresses 61 CVEs (CVE-2023-36761)
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Tenable
Microsoft’s August 2023 Patch Tuesday Addresses 73 CVEs (CVE-2023-38180)
blogs_tenable·2023-08-08·CVSS 7.5
[HIGH] Microsoft’s August 2023 Patch Tuesday Addresses 73 CVEs (CVE-2023-38180)
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Securelist
Non-mobile malware statistics, Q1 2023
blogs_securelist·2023-06-07
Non-mobile malware statistics, Q1 2023
Table of Contents
- Quarterly figures
- Financial threats
- Ransomware programs
- Most prolific groups
- Miners
- Vulnerable applications used in cyberattacks
- Attacks on macOS
- IoT attacks
- Attacks via web resources
- Local threats
Authors
- AMR
- IT threat evolution in Q1 2023
- IT threat evolution in Q1 2023. Non-mobile statistics
- IT threat evolution in Q1 2023. Mobile statistics
These statistics are based on detection verdicts of Kaspersky products and services received from users who consented to providing statistical data.
## Quarterly figures
According to Kaspersky Security Network, in Q1 2023:
- Kaspersky solutions blocked 865,071,227 attacks launched from online resources across the globe.
- Web Anti-Virus detected 246,912,694 unique URLs.
- Attempts to run malware fo
Securelist
IT threat evolution in Q1 2023. Non-mobile statistics
blogs_securelist·2023-06-07
IT threat evolution in Q1 2023. Non-mobile statistics
Table of Contents
Quarterly figures
Financial threats
Financial threat statistics
Geography of financial malware attacks
Ransomware programs
Quarterly trends and highlights
Attacks on Linux and VMWare ESXi servers
Progress in combating cybercrime
Conti-based Trojan decrypted
Most prolific groups
Number of new modifications
Number of users attacked by ransomware Trojans
Geography of attacked users
TOP 10 most common families of ransomware Trojans
Miners
Number of new miner modifications
Number of users attacked by miners
Geography of miner attacks
Vulnerable applications used in cyberattacks
Quarterly highlights
Vulnerability statistics
Attacks on macOS
Geography of threats for macOS
IoT attacks
IoT threat statistics
Attacks via web resources
Countries/territories
Securelist
Nokoyawa ransomware attacks with Windows zero-day
blogs_securelist·2023-04-11·CVSS 7.8
[HIGH] Nokoyawa ransomware attacks with Windows zero-day
Table of Contents
- Elevation-of-privilege exploit
- Post exploitation and malware
- Conclusions
- Indicators of compromise
Authors
- Boris Larin
Updated April 20, 2023
In February 2023, Kaspersky technologies detected a number of attempts to execute similar elevation-of-privilege exploits on Microsoft Windows servers belonging to small and medium-sized businesses in the Middle East, in North America, and previously in Asia regions. These exploits were very similar to already known Common Log File System (CLFS) driver exploits that we analyzed previously, but we decided to double check and it was worth it – one of the exploits turned out to be a zero-day, supporting different versions and builds of Windows, including Windows 11. The exploit was highly obfuscated with more than 80% of
Tenable
Microsoft’s April 2023 Patch Tuesday Addresses 97 CVEs (CVE-2023-28252)
blogs_tenable·2023-04-11·CVSS 7.8
[HIGH] Microsoft’s April 2023 Patch Tuesday Addresses 97 CVEs (CVE-2023-28252)
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Securelist
Nokoyawa ransomware attacks with Windows zero-day
blogs_securelist·2023-04-11·CVSS 7.8
[HIGH] Nokoyawa ransomware attacks with Windows zero-day
Table of Contents
Elevation-of-privilege exploit
Post exploitation and malware
Conclusions
Indicators of compromise
Authors
Boris Larin
Updated April 20, 2023
In February 2023, Kaspersky technologies detected a number of attempts to execute similar elevation-of-privilege exploits on Microsoft Windows servers belonging to small and medium-sized businesses in the Middle East, in North America, and previously in Asia regions. These exploits were very similar to already known Common Log File System (CLFS) driver exploits that we analyzed previously, but we decided to double check and it was worth it – one of the exploits turned out to be a zero-day, supporting different versions and builds of Windows, including Windows 11. The exploit was highly obfuscated with more than 80% of the its
Checkpoint
20th February – Threat Intelligence Report
blogs_checkpoint·2023-02-20
CVE-2023-21823 20th February – Threat Intelligence Report
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## 20th February – Threat Intelligence Report
For the latest discoveries in cyber research for the week of 20th February, please download our Threat_Intelligence Bulletin
TOP ATTACKS AND BREACHES
Check Point Research identified a campaign against entities in Armenia, using a new version of OxtaRAT – an AutoIt-based backdoor for remote access and desktop surveillance. The threat actors have been targeting human rights organizations, dissidents, and independent media in Azerbaijan for several years, amid rising tens
Talos
Threat Source newsletter (Feb. 16, 2023) — Recapping what we may have missed so far this year
blogs_talos·2023-02-16
Threat Source newsletter (Feb. 16, 2023) — Recapping what we may have missed so far this year
## Threat Source newsletter (Feb. 16, 2023) — Recapping what we may have missed so far this year
Welcome to this week’s edition of the Threat Source newsletter.
I am back after more than three months away from Talos on parental leave. Having a baby really resets your expectations for “keeping up” with the world. From November through mid-January or so I had no idea what was going on with the outside world, I only cared about my daughter’s feeding schedule and tried to squeeze in 30-minute naps where I could.
I’ve slowly started to re-introduce myself to social media and the news world at large over the past few weeks so my return to work wasn’t so abrupt, and I missed quite a bit. There was a stretch there where I was only getting the latest headlines from Weekend Update on “Saturday Ni
Talos
Threat Source newsletter (Feb. 16, 2023) — Recapping what we may have missed so far this year
blogs_talos·2023-02-16
Threat Source newsletter (Feb. 16, 2023) — Recapping what we may have missed so far this year
Welcome to this week’s edition of the Threat Source newsletter.
I am back after more than three months away from Talos on parental leave. Having a baby really resets your expectations for “keeping up” with the world. From November through mid-January or so I had no idea what was going on with the outside world, I only cared about my daughter’s feeding schedule and tried to squeeze in 30-minute naps where I could.
I’ve slowly started to re-introduce myself to social media and the news world at large over the past few weeks so my return to work wasn’t so abrupt, and I missed quite a bit. There was a stretch there where I was only getting the latest headlines from Weekend Update on “Saturday Night Live.”
My teammates Madison Burns and Bill Largent did a fantastic job filling in for me on t
Qualys
The February 2023 Patch Tuesday Security Update Review
blogs_qualys·2023-02-15
The February 2023 Patch Tuesday Security Update Review
## Table of Contents
Microsoft Patches for February2023
Adobe Patches for February2023
Notable and Critical Microsoft Vulnerabilities Patched
Other Microsoft Vulnerability Highlights
Microsoft Release Summary
Discover and Prioritize Vulnerabilities in Vulnerability Management, Detection & Response (VMDR)
Rapid Response with Patch Management (PM)
EVALUATE Vendor-Suggested Mitigation with Policy Compliance (PC)
Qualys Monthly Webinar Series
This Month in Vulnerabilities & Patches
Microsoft and Adobe have released several monthly security fixes and updates for their products. Let’s take a look at the highlights of this month’s Patch Tuesday as we review and discuss the security updates.
## Microsoft Patches for February 2023
Microsoft has patched 79 vulnerabilities this month, in
Qualys
The February 2023 Patch Tuesday Security Update Review | Qualys
blogs_qualys·2023-02-15
The February 2023 Patch Tuesday Security Update Review | Qualys
#### Table of Contents
- Microsoft Patches for February2023
- Adobe Patches for February2023
- Notable and Critical Microsoft Vulnerabilities Patched
- Other Microsoft Vulnerability Highlights
- Microsoft Release Summary
- Discover and Prioritize Vulnerabilities in Vulnerability Management, Detection & Response (VMDR)
- Rapid Response with Patch Management (PM)
- EVALUATE Vendor-Suggested Mitigation with Policy Compliance (PC)
- Qualys Monthly Webinar Series
- This Month in Vulnerabilities & Patches
Microsoft and Adobe have released several monthly security fixes and updates for their products. Let’s take a look at the highlights of this month’s Patch Tuesday as we review and discuss the security updates.
## Microsoft Patches for February 2023
Microsoft has patched 79 vulnerabilities t
Talos
Microsoft Patch Tuesday for February 2023 — Snort rules and prominent vulnerabilities
blogs_talos·2023-02-14·CVSS 9.8
CVE-2023-21823 [CRITICAL] Microsoft Patch Tuesday for February 2023 — Snort rules and prominent vulnerabilities
Microsoft released its monthly security update on Tuesday, disclosing 73 vulnerabilities. Of these vulnerabilities, 8 are classified as “Critical”, 64 are classified as “Important”, one vulnerability is classified as “Moderate.”
According to Microsoft none of the vulnerabilities has been publicly disclosed before Patch Tuesday and only three vulnerabilities were seen in the wild. The most serious one is CVE-2023-21823 a Windows Graphics Component Remote Code Execution Vulnerability. Followed by CVE-2023-21715 a Microsoft Publisher Security Features Bypass Vulnerability which we are describing below and CVE-2023-23376 a local Windows Common Log File System Driver Elevation of Privilege Vulnerability.
Three of the most “Critical“ vulnerabilities, which Microsoft considers to be “more likel
Tenable
Microsoft’s February 2023 Patch Tuesday Addresses 75 CVEs (CVE-2023-23376)
blogs_tenable·2023-02-14·CVSS 7.8
[HIGH] Microsoft’s February 2023 Patch Tuesday Addresses 75 CVEs (CVE-2023-23376)
## Cloud Exposure
Tenable Cloud Security (CNAPP) Request a demo
Tenable Cloud Vulnerability Management Request a demo
Tenable CIEM Request a demo
Secure your cloud
## Vulnerability Exposure
Tenable Vulnerability Management Try for free
Tenable Security Center Request a demo
Tenable Web App Scanning Try for free
Tenable Patch Management Request a demo
Tenable Enclave Security Request a demo
Tenable Attack Surface Management Request a demo
Tenable Nessus Try for free
## AI Exposure
Tenable AI Exposure Request a demo
## OT/IoT Exposure
Tenable OT Security Request a demo
## Identity Exposure
Tenable Identity Exposure Request a demo
## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Krebs
Microsoft Patch Tuesday, February 2023 Edition
blogs_krebs·2023-02-14·CVSS 7.3
CVE-2023-23376 [HIGH] Microsoft Patch Tuesday, February 2023 Edition
Microsoft is sending the world a whole bunch of love today, in the form of patches to plug dozens of security holes in its Windows operating systems and other software. This year’s special Valentine’s Day Patch Tuesday includes fixes for a whopping three different “zero-day” vulnerabilities that are already being used in active attacks.
Microsoft’s security advisories are somewhat sparse with details about the zero-day bugs. Redmond flags CVE-2023-23376 as an “Important” elevation of privilege vulnerability in the Windows Common Log File System Driver , which is present in Windows 10 and 11 systems, as well as many server versions of Windows.
“Sadly, there’s just a little solid information about this privilege escalation,” said Dustin Childs , head of threat awareness at Trend Micro’s Ze
Talos
Microsoft Patch Tuesday for February 2023 — Snort rules and prominent vulnerabilities
blogs_talos·2023-02-14·CVSS 9.8
[CRITICAL] Microsoft Patch Tuesday for February 2023 — Snort rules and prominent vulnerabilities
## Microsoft Patch Tuesday for February 2023 — Snort rules and prominent vulnerabilities
Microsoft released its monthly security update on Tuesday, disclosing 73 vulnerabilities. Of these vulnerabilities, 8 are classified as “Critical”, 64 are classified as “Important”, one vulnerability is classified as “Moderate.”
According to Microsoft none of the vulnerabilities has been publicly disclosed before Patch Tuesday and only three vulnerabilities were seen in the wild. The most serious one is CVE-2023-21823 a Windows Graphics Component Remote Code Execution Vulnerability. Followed by CVE-2023-21715 a Microsoft Publisher Security Features Bypass Vulnerability which we are describing below and CVE-2023-23376 a local Windows Common Log File System Driver Elevation of Privilege Vulnerability.
Krebs
Microsoft Patch Tuesday, February 2023 Edition
blogs_krebs·2023-02-14·CVSS 7.3
CVE-2023-23376 [HIGH] Microsoft Patch Tuesday, February 2023 Edition
Microsoft is sending the world a whole bunch of love today, in the form of patches to plug dozens of security holes in its Windows operating systems and other software. This year’s special Valentine’s Day Patch Tuesday includes fixes for a whopping three different “zero-day” vulnerabilities that are already being used in active attacks.
Microsoft’s security advisories are somewhat sparse with details about the zero-day bugs. Redmond flags CVE-2023-23376 as an “Important” elevation of privilege vulnerability in the Windows Common Log File System Driver, which is present in Windows 10 and 11 systems, as well as many server versions of Windows.
“Sadly, there’s just a little solid information about this privilege escalation,” said Dustin Childs, head of threat awareness at Trend Micro’s Zero
Securelist
New win32k zero day: CVE-2019-0859
blogs_securelist·2019-04-15·CVSS 7.8
CVE-2019-0859 [HIGH] New win32k zero day: CVE-2019-0859
Authors
- Vasily Berdnikov
- Boris Larin
- Anton Ivanov
In March 2019, our automatic Exploit Prevention (EP) systems detected an attempt to exploit a vulnerability in the Microsoft Windows operating system. Further analysis of this event led to us discovering a zero-day vulnerability in win32k.sys. It was the fifth consecutive exploited Local Privilege Escalation vulnerability in Windows that we have discovered in recent months using our technologies. The previous ones were:
- Zero-day exploit (CVE-2018-8453) used in targeted attacks
- A new exploit for zero-day vulnerability CVE-2018-8589
- Zero-day in Windows Kernel Transaction Manager (CVE-2018-8611)
- The fourth horseman: CVE-2019-0797 vulnerability
On March 17, 2019 we reported our discovery to Microsoft; the company confirmed the
Securelist
The King is dead. Long live the King!
blogs_securelist·2018-05-09·CVSS 7.5
CVE-2018-8174 [HIGH] The King is dead. Long live the King!
Authors
- Vladislav Stolyarov
- Boris Larin
- Anton Ivanov
## Root cause analysis of the latest Internet Explorer zero day – CVE-2018-8174
In late April 2018, a new zero-day vulnerability for Internet Explorer (IE) was found using our sandbox; more than two years since the last in the wild example (CVE-2016-0189). This particular vulnerability and subsequent exploit are interesting for many reasons. The following article will examine the core reasons behind the latest vulnerability, CVE-2018-8174.
### Searching for the zero day
Our story begins on VirusTotal (VT), where someone uploaded an interesting exploit on April 18, 2018. This exploit was detected by several AV vendors including Kaspersky, specifically by our generic heuristic logic for some older Microsoft Word exploits.
After
Securelist
Disappearing bytes: Reverse engineering the MS Office RTF parser
blogs_securelist·2018-02-21
Disappearing bytes: Reverse engineering the MS Office RTF parser
Table of Contents
- State reset
- Final destination
- Fixed-size buffer
- Unnecessary data
- Kind of magic
- Conclusion
Authors
- Boris Larin
Microsoft Office was a prime target for attacks in 2017. As well as the large number of vulnerabilities discovered and proof-of-concept exploits published, malware authors felt it necessary to prevent detection of ‘one-day’ and ‘old-day’ exploits by antivirus software. It also became clear that using RTF parsing features and peculiarities are no longer enough to effectively evade detection. Along with the rise of MS Office exploitation, when RTF is used as a container for an exploit, we encountered lots of samples that were ‘exploiting’ the implementation of Microsoft Word’s RTF parser to confuse all other third-party RTF parsers, including thos
Crowdstrike
February 2023 Patch Tuesday: Updates and Analysis
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] February 2023 Patch Tuesday: Updates and Analysis
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How Charlotte AI AgentWorks Fuels Security's Agentic Ecosystem Mar 25, 2026
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How Charlotte AI AgentWorks Fuels Security's Agentic Ecosystem Mar 25, 2026
Video Highlights the 4 Key Steps to Successful Incident Response Dec 02, 2019
Helping Non-Security Stakeholders Understand ATT&CK in 10 Minutes or Less [VI
Zscaler
Zscaler found Windows Security Vulnerabilities | 02-14-2023
blogs_zscaler·CVSS 7.8
[HIGH] Zscaler found Windows Security Vulnerabilities | 02-14-2023
Provide users with seamless, secure, reliable access to applications and data.
Build and run secure cloud apps, enable zero trust cloud connectivity, and protect workloads from data center to cloud.
Provide zero trust connectivity for IoT and OT devices and secure remote access to OT systems.
Provide zero trust site-to-site connectivity and reliable access to B2B apps for partners.
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Zscaler: A Leader in the 2025 Gartner® Magic Quadrant™ for Security Service Edge (SSE)
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Crowdstrike
February 2023 Patch Tuesday: Updates and Analysis
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] February 2023 Patch Tuesday: Updates and Analysis
How CrowdStrike is Accelerating Exposure Evaluation as Adversaries Gain Speed Apr 06, 2026
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How CrowdStrike is Accelerating Exposure Evaluation as Adversaries Gain Speed Apr 06, 2026
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
Video Highlights the 4 Key Steps to Successful Incident Response Dec 02, 2019
Helping Non-Security Stakeholders Understand AT
2023-02-14
Published
2023-02-14
Added to CISA KEV
Exploited in the wild