Known exploited · GNU
CVE-2023-4911: GNU C Library Buffer Overflow Vulnerability
What it is
GNU C Library's dynamic loader ld.so contains a buffer overflow vulnerability when processing the GLIBC_TUNABLES environment variable, allowing a local attacker to execute code with elevated privileges.
- Vendor
- GNU
- Product
- GNU C Library
- Added to KEV
- November 21, 2023
- CISA due date
- December 12, 2023
- Ransomware use
- Unknown
What CISA requires
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Forensic triage
No
What to do now
- Find every instance of GNU C Library you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before December 12, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.