CVE-2021-26427
published 2021-10-13CVE-2021-26427: Microsoft Exchange Server Remote Code Execution Vulnerability
PriorityP352critical9.6CVSS 3.1
AVAACLPRNUINSCCHIHAH
EPSS
0.87%
54.8th percentile
Microsoft Exchange Server Remote Code Execution Vulnerability
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | exchange_server | — | — |
| microsoft | exchange_server | — | — |
| microsoft | exchange_server | — | — |
| microsoft | microsoft_exchange_server_2013_cumulative_update_23 | >= 15.00.0 < 15.00.1497.024 | 15.00.1497.024 |
| microsoft | microsoft_exchange_server_2016_cumulative_update_21 | >= 15.01.0 < 15.01.2308.015 | 15.01.2308.015 |
| microsoft | microsoft_exchange_server_2016_cumulative_update_22 | >= 15.0.0 < 15.01.2375.012 | 15.01.2375.012 |
| microsoft | microsoft_exchange_server_2019_cumulative_update_10 | >= 15.02.0 < 15.02.0922.014 | 15.02.0922.014 |
| microsoft | microsoft_exchange_server_2019_cumulative_update_11 | >= 15.02.0 < 15.02.0986.009 | 15.02.0986.009 |
| msrc | microsoft_exchange_server_2013_cumulative_update_23 | — | — |
| msrc | microsoft_exchange_server_2016_cumulative_update_21 | — | — |
| msrc | microsoft_exchange_server_2016_cumulative_update_22 | — | — |
| msrc | microsoft_exchange_server_2019_cumulative_update_10 | — | — |
| msrc | microsoft_exchange_server_2019_cumulative_update_11 | — | — |
CVSS provenance
nvdv3.19.6CRITICALCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
nvdv2.05.8MEDIUMAV:A/AC:L/Au:N/C:P/I:P/A:P
vendor_msrc9.0CRITICAL
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Microsoft
Microsoft Exchange Server Remote Code Execution Vulnerability
vendor_msrc·2021-10-12·CVSS 9.0
CVE-2021-26427 [CRITICAL] Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server Remote Code Execution Vulnerability
FAQ: According to the CVSS metric, the attack vector is adjacent (AV:A). What does that mean for this vulnerability?
This vulnerability's attack is limited at the protocol level to a logically adjacent topology. This means it cannot simply be done across the internet, but instead needs something specific tied to the target. Good examples would include the same shared physical network (such as Bluetooth or IEEE 802.11), logical network (local IP subnet), or from within a secure or otherwise limited administrative domain (MPLS, secure VPN to an administrative network zone). This is common to many attacks that require machine-in-the-middle (MITM) type setups or that rely on initially gaining a foothold in another environment.
FAQ
GHSA
GHSA-wwfc-ph8v-qxf5: Microsoft Exchange Server Remote Code Execution Vulnerability
ghsa_unreviewed·2022-05-24
CVE-2021-26427 [CRITICAL] GHSA-wwfc-ph8v-qxf5: Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server Remote Code Execution Vulnerability
No detection rules found.
No public exploits indexed.
Qualys
Microsoft & Adobe Patch Tuesday (October 2021) – Microsoft 74 Vulnerabilities with 3 Critical, 4 Zero-Days. Adobe 10 Vulnerabilities
blogs_qualys·2021-10-13·CVSS 9.0
CVE-2021-40449 [CRITICAL] Microsoft & Adobe Patch Tuesday (October 2021) – Microsoft 74 Vulnerabilities with 3 Critical, 4 Zero-Days. Adobe 10 Vulnerabilities
## Microsoft Patch Tuesday – October 2021
Microsoft patched 74 vulnerabilities in their October 2021 Patch Tuesday release, of which three are rated as critical severity and four were previously reported as zero-days.
## Critical Microsoft Vulnerabilities Patched
CVE-2021-40449 – Win32k Elevation of Privilege Vulnerability
This was a zero-day, and one of the four addressed by Microsoft this month. This vulnerability impacts the Win32K kernel driver. This is being actively exploited by IronHusky and Chinese APT groups. Microsoft has assigned a CVSSv3 base score of 7.8 to this vulnerability and it should be prioritized for patching.
CVE-2021- 40486 – Microsoft Word Remote Code Execution Vulnerability
This vulnerability is due to improper input validation in Microsoft Word. Adversaries
Krebs
Patch Tuesday, October 2021 Edition
blogs_krebs·2021-10-13·CVSS 7.8
[HIGH] Patch Tuesday, October 2021 Edition
Microsoft today issued updates to plug more than 70 security holes in its Windows operating systems and other software, including one vulnerability that is already being exploited. This month’s Patch Tuesday also includes security fixes for the newly released Windows 11 operating system. Separately, Apple has released updates for iOS and iPadOS to address a flaw that is being actively attacked.
Firstly, Apple has released iOS 15.0.2 and iPadOS 15.0.2 to fix a zero-day vulnerability (CVE-2021-30883) that is being leveraged in active attacks targeting iPhone and iPad users. Lawrence Abrams of Bleeping Computer writes that the flaw could be used to steal data or install malware, and that soon after Apple patched the bug security researcher Saar Amar published a technical writeup and proof-of
Qualys
Microsoft & Adobe Patch Tuesday (October 2021) – Microsoft 74 Vulnerabilities with 3 Critical, 4 Zero-Days. Adobe 10 Vulnerabilities | Qualys
blogs_qualys·2021-10-13·CVSS 9.0
CVE-2021-40449 [CRITICAL] Microsoft & Adobe Patch Tuesday (October 2021) – Microsoft 74 Vulnerabilities with 3 Critical, 4 Zero-Days. Adobe 10 Vulnerabilities | Qualys
### Microsoft Patch Tuesday – October 2021
Microsoft patched 74 vulnerabilities in their October 2021 Patch Tuesday release, of which three are rated as critical severity and four were previously reported as zero-days.
### Critical Microsoft Vulnerabilities Patched
CVE-2021-40449 – Win32k Elevation of Privilege Vulnerability
This was a zero-day, and one of the four addressed by Microsoft this month. This vulnerability impacts the Win32K kernel driver. This is being actively exploited by IronHusky and Chinese APT groups. Microsoft has assigned a CVSSv3 base score of 7.8 to this vulnerability and it should be prioritized for patching.
CVE-2021- 40486 – Microsoft Word Remote Code Execution Vulnerability
This vulnerability is due to improper input validation in Microsoft Word. Adversarie
Tenable
Microsoft’s October 2021 Patch Tuesday Addresses 74 CVEs (CVE-2021-40449)
blogs_tenable·2021-10-12·CVSS 7.8
[HIGH] Microsoft’s October 2021 Patch Tuesday Addresses 74 CVEs (CVE-2021-40449)
## Cloud Exposure
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## Business needs
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Talos
Microsoft Patch Tuesday for Oct. 2021 — Snort rules and prominent vulnerabilities
blogs_talos·2021-10-12·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for Oct. 2021 — Snort rules and prominent vulnerabilities
## Microsoft Patch Tuesday for Oct. 2021 — Snort rules and prominent vulnerabilities
By Jon Munshaw, with contributions from Asheer Malhotra.
Microsoft released its monthly security update Tuesday, disclosing 78 vulnerabilities in the company’s various software, hardware and firmware offerings.
This month’s release is particularly notable because there are only two critical vulnerabilities included, with the rest being important. This is the fewest number of critical vulnerabilities disclosed as part of a Patch Tuesday in at least a year.
CVE-2021-40461 is one of the critical vulnerabilities — a flaw in the Network Virtualization Service Provider that could allow an attacker to execute remote code on the target machine. This vulnerability has a severity rating of 9.9 out of a possible
Krebs
Patch Tuesday, October 2021 Edition
blogs_krebs·2021-10-12·CVSS 7.8
[HIGH] Patch Tuesday, October 2021 Edition
Microsoft today issued updates to plug more than 70 security holes in its Windows operating systems and other software, including one vulnerability that is already being exploited. This month’s Patch Tuesday also includes security fixes for the newly released Windows 11 operating system. Separately, Apple has released updates for iOS and iPadOS to address a flaw that is being actively attacked.
Firstly, Apple has released iOS 15.0.2 and iPadOS 15.0.2 to fix a zero-day vulnerability (CVE-2021-30883) that is being leveraged in active attacks targeting iPhone and iPad users. Lawrence Abrams of Bleeping Computer writes that the flaw could be used to steal data or install malware, and that soon after Apple patched the bug security researcher Saar Amar published a technical writeup and proof-of
Talos
Microsoft Patch Tuesday for Oct. 2021 — Snort rules and prominent vulnerabilities
blogs_talos·2021-10-12·CVSS 8.8
CVE-2021-40461 [HIGH] Microsoft Patch Tuesday for Oct. 2021 — Snort rules and prominent vulnerabilities
By Jon Munshaw, with contributions from Asheer Malhotra.
Microsoft released its monthly security update Tuesday, disclosing 78 vulnerabilities in the company’s various software, hardware and firmware offerings.
This month’s release is particularly notable because there are only two critical vulnerabilities included, with the rest being important. This is the fewest number of critical vulnerabilities disclosed as part of a Patch Tuesday in at least a year.
CVE-2021-40461 is one of the critical vulnerabilities — a flaw in the Network Virtualization Service Provider that could allow an attacker to execute remote code on the target machine. This vulnerability has a severity rating of 9.9 out of a possible 10, virtually the highest severity rating seen in Patch Tuesdays.
The other critical
Crowdstrike
October 2021 Patch Tuesday: Updates and Analysis
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] October 2021 Patch Tuesday: Updates and Analysis
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Helping Non-Security Stakeholders Understand AT
2021-10-13
Published