CVE-2021-31962
published 2021-06-08CVE-2021-31962: Kerberos AppContainer Security Feature Bypass Vulnerability
PriorityP356critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
3.81%
88.8th percentile
Kerberos AppContainer Security Feature Bypass Vulnerability
Affected
48 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10_version_1507 | >= 10.0.0 < 10.0.10240.18967 | 10.0.10240.18967 |
| microsoft | windows_10_version_1607 | >= 10.0.0 < 10.0.14393.4467 | 10.0.14393.4467 |
| microsoft | windows_10_version_1809 | >= 10.0.0 < 10.0.17763.1999 | 10.0.17763.1999 |
| microsoft | windows_10_version_1909 | >= 10.0.0 < 10.0.18363.1621 | 10.0.18363.1621 |
| microsoft | windows_10_version_2004 | >= 10.0.0 < 10.0.19041.1052 | 10.0.19041.1052 |
| microsoft | windows_10_version_20h2 | >= 10.0.0 < 10.0.19042.1052 | 10.0.19042.1052 |
| microsoft | windows_10_version_21h1 | >= 10.0.0 < 10.0.19043.1052 | 10.0.19043.1052 |
| microsoft | windows_7 | >= 6.1.0 < 6.1.7601.25632 | 6.1.7601.25632 |
| microsoft | windows_7_service_pack_1 | >= 6.1.0 < 6.1.7601.25632 | 6.1.7601.25632 |
| microsoft | windows_8.1 | >= 6.3.0 < 6.3.9600.20045 | 6.3.9600.20045 |
| microsoft | windows_8.1 | >= 6.3.0 < 6.3.9600.20044 | 6.3.9600.20044 |
| microsoft | windows_server_2008 | — | — |
| microsoft | windows_server_2008 | — | — |
| microsoft | windows_server_2008_r2_service_pack_1 | >= 6.0.0 < 6.1.7601.25632 | 6.1.7601.25632 |
| microsoft | windows_server_2008_r2_service_pack_1 | >= 6.1.0 < 6.1.7601.25632 | 6.1.7601.25632 |
| microsoft | windows_server_2008_service_pack_2 | >= 6.0.0 < 6.0.6003.21137 | 6.0.6003.21137 |
| microsoft | windows_server_2012 | — | — |
| microsoft | windows_server_2012 | >= 6.2.0 < 6.2.9200.23372 | 6.2.9200.23372 |
| microsoft | windows_server_2012_r2 | >= 6.3.0 < 6.3.9600.20045 | 6.3.9600.20045 |
Detection & IOCsextracted from sources · hover to see the quote
- →Focus detection on Kerberos SPN negotiation and LSASS authentication attempts originating from sandboxed AppContainer processes, which should not normally perform such operations. ↗
- →Monitor for AppContainer processes (low-integrity sandboxed processes) making unexpected Kerberos authentication calls to LSASS, which may indicate an attempted security feature bypass. ↗
- ·Exploit status is publicly disclosed: No and exploited in the wild: No at time of advisory publication. Exploitation is rated 'Less Likely' for both latest and older software releases, reducing urgency but not eliminating risk. ↗
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
vendor_msrc9.4CRITICAL
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Microsoft
Kerberos AppContainer Security Feature Bypass Vulnerability
vendor_msrc·2021-06-08·CVSS 9.4
CVE-2021-31962 [CRITICAL] Kerberos AppContainer Security Feature Bypass Vulnerability
Kerberos AppContainer Security Feature Bypass Vulnerability
FAQ: What kind of security feature could be bypassed by successfully exploiting this vulnerability?
This vulnerability applies to Kerberos Service Principal Name (SPN) negotiation and subsequent LSASS (Local Security Authority Subsystem Service) authentication for sandboxed AppContainer processes.
Windows Kerberos: Windows Kerberos
Microsoft: Microsoft
Impact: Security Feature Bypass
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.update.microsoft.com/v7/site/Search.aspx?q=KB5003646
Reference: https://support.microsoft.com/help/5003646
Reference: https://catalog.update.microsoft.com/v7/site
GHSA
GHSA-775h-j8rj-hfwp: Kerberos AppContainer Security Feature Bypass Vulnerability
ghsa_unreviewed·2022-05-24
CVE-2021-31962 [CRITICAL] GHSA-775h-j8rj-hfwp: Kerberos AppContainer Security Feature Bypass Vulnerability
Kerberos AppContainer Security Feature Bypass Vulnerability
No detection rules found.
No public exploits indexed.
Qualys
Microsoft & Adobe Patch Tuesday (June 2021) – Microsoft 50 Vulnerabilities with 5 Critical, Adobe 21 Critical Vulnerabilities
blogs_qualys·2021-06-08·CVSS 5.2
CVE-2021-31985 [MEDIUM] Microsoft & Adobe Patch Tuesday (June 2021) – Microsoft 50 Vulnerabilities with 5 Critical, Adobe 21 Critical Vulnerabilities
## Microsoft Patch Tuesday – June 2021
Microsoft patched 50 CVEs in their June 2021 Patch Tuesday release, and five of them are rated as critical severity. Six have applicable exploits.
## Critical Microsoft Vulnerabilities Patched
CVE-2021-31985 – Microsoft Defender Remote Code Execution Vulnerability
Microsoft released patches addressing a critical RCE vulnerability in its Defender product (CVE-2021-31985). This CVE has a high likelihood of exploitability and is assigned a CVSSv3 base score of 7.8 by the vendor.
CVE-2021-31959 – Scripting Engine Memory Corruption Vulnerability
Microsoft released patches addressing a critical memory corruption vulnerability in the Chakra JScript scripting engine. This vulnerability impacts Windows RT, Windows 7, Windows 8, Windows 10, Windows Server
Crowdstrike
June 2021 Patch Tuesday: Updates and Analysis
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] June 2021 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
Crowdstrike
June 2021 Patch Tuesday: Updates and Analysis
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] June 2021 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
http://packetstormsecurity.com/files/163206/Windows-Kerberos-AppContainer-Enterprise-Authentication-Capability-Bypass.htmlhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31962http://packetstormsecurity.com/files/163206/Windows-Kerberos-AppContainer-Enterprise-Authentication-Capability-Bypass.htmlhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31962
2021-06-08
Published