Microsoft Windows CSRSS Security Feature Bypass Vulnerability
The Client-Server Run-time Subsystem (CSRSS) in Microsoft Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 mismanages process tokens, which allows local users to gain privileges via a crafted…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 4 / 5
- KEV catalog (CISA)28 Mar 2022
- Exploited in EUVD (ENISA)28 Mar 2022
- Used by ransomwareyes
- EPSS above 10 %62.8%
- No account, over the networkno
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply updates per vendor instructions.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
The Client-Server Run-time Subsystem (CSRSS) in Microsoft Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 mismanages process tokens, which allows local users to gain privileges via a crafted application, aka "Windows CSRSS Security Feature Bypass Vulnerability."
Affected products
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
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Published
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Exploitation reported (ENISA)
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Added to the KEV catalog
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CISA remediation due date
-
EPSS peak: 62.9%
References
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