CVE-2021-34458
published 2021-07-16CVE-2021-34458: Windows Kernel Remote Code Execution Vulnerability
PriorityP263critical9.9CVSS 3.1
AVNACLPRLUINSCCHIHAH
EPSS
2.63%
85.4th percentile
Windows Kernel Remote Code Execution Vulnerability
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_server_2016 | — | — |
| microsoft | windows_server_2016 | — | — |
| microsoft | windows_server_2016 | >= 10.0.14393.0 < 10.0.14393.4530 | 10.0.14393.4530 |
| microsoft | windows_server_2019 | >= 10.0.17763.0 < 10.0.17763.2061 | 10.0.17763.2061 |
| microsoft | windows_server_version_2004 | >= 10.0.0 < 10.0.19041.1110 | 10.0.19041.1110 |
| microsoft | windows_server_version_20h2 | >= 10.0.0 < 10.0.19042.1110 | 10.0.19042.1110 |
| msrc | windows_server_2016 | — | — |
| msrc | windows_server_2019 | — | — |
| msrc | windows_server_version_2004 | — | — |
| msrc | windows_server_version_20h2 | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →Vulnerability is exploitable only when Windows host is running virtual machines AND the server hardware includes SR-IOV (Single Root Input/Output Virtualization) devices assigned to guests ↗
- →Scope detection: assess exposure by confirming both conditions — Windows instance hosting VMs AND SR-IOV-capable hardware present ↗
- ·Exploitation assessed as 'Less Likely' for both latest and older software releases; no public exploit or in-the-wild exploitation confirmed at time of advisory ↗
- ·Attack vector is within a virtualized environment — a malicious or compromised SR-IOV guest could interfere with PCIe siblings on other guests or the root partition; not a traditional network-facing RCE ↗
CVSS provenance
nvdv3.19.9CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
nvdv2.09.0CRITICALAV:N/AC:L/Au:S/C:C/I:C/A:C
vendor_msrc9.9CRITICAL
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GHSA
GHSA-m46m-7gj5-vvwm: Windows Kernel Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-34458
ghsa_unreviewed·2022-05-24·CVSS 9.9
CVE-2021-34508 [CRITICAL] GHSA-m46m-7gj5-vvwm: Windows Kernel Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-34458
Windows Kernel Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-34458.
GHSA
GHSA-35fh-hcwr-mcv6: Windows Kernel Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-34508
ghsa_unreviewed·2022-05-24·CVSS 8.8
CVE-2021-34458 [HIGH] GHSA-35fh-hcwr-mcv6: Windows Kernel Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-34508
Windows Kernel Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-34508.
Microsoft
Windows Kernel Remote Code Execution Vulnerability
vendor_msrc·2021-07-13·CVSS 9.9
CVE-2021-34458 [CRITICAL] Windows Kernel Remote Code Execution Vulnerability
Windows Kernel Remote Code Execution Vulnerability
FAQ: How do I know if I'm affected by this vulnerability?
This issue allows a single root input/output virtualization (SR-IOV) device which is assigned to a guest to potentially interfere with its Peripheral Component Interface Express (PCIe) siblings which are attached to other guests or to the root.
You will be vulnerable if you implement the following:
Your Windows instance is hosting virtual machines
Your Server includes the required hardware with SR-IOV devices
Windows Kernel: Windows Kernel
Microsoft: Microsoft
Impact: Remote Code Execution
Exploit Status: Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely;Older Software Release:Exploitation Less Likely;DOS:N/A
Reference: https://catalog.updat
No detection rules found.
No public exploits indexed.
Krebs
Microsoft Patch Tuesday, July 2021 Edition
blogs_krebs·2021-07-13·CVSS 7.8
[HIGH] Microsoft Patch Tuesday, July 2021 Edition
Microsoft today released updates to patch at least 116 security holes in its Windows operating systems and related software. At least four of the vulnerabilities addressed today are under active attack, according to Microsoft.
Thirteen of the security bugs quashed in this month’s release earned Microsoft’s most-dire “critical” rating, meaning they can be exploited by malware or miscreants to seize remote control over a vulnerable system without any help from users.
Another 103 of the security holes patched this month were flagged as “important,” which Microsoft assigns to vulnerabilities “whose exploitation could result in compromise of the confidentiality, integrity, or availability of user data, or of the integrity or availability of processing resources.”
Among the critical bugs is o
Krebs
Microsoft Patch Tuesday, July 2021 Edition
blogs_krebs·2021-07-13·CVSS 7.8
[HIGH] Microsoft Patch Tuesday, July 2021 Edition
Microsoft today released updates to patch at least 116 security holes in its Windows operating systems and related software. At least four of the vulnerabilities addressed today are under active attack, according to Microsoft.
Thirteen of the security bugs quashed in this month’s release earned Microsoft’s most-dire “critical” rating, meaning they can be exploited by malware or miscreants to seize remote control over a vulnerable system without any help from users.
Another 103 of the security holes patched this month were flagged as “important,” which Microsoft assigns to vulnerabilities “whose exploitation could result in compromise of the confidentiality, integrity, or availability of user data, or of the integrity or availability of processing resources.”
Among the critical bugs is o
Crowdstrike
July 2021 Patch Tuesday: Updates and Analysis
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Crowdstrike
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blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] July 2021 Patch Tuesday: Updates and Analysis
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
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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
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Video Highlights the 4 Key Steps to Successful Incident Response Dec 02, 2019
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2021-07-16
Published