What’s Vulnerable › Vulnerabilities
CVE-2023-6779: Glibc: off-by-one heap-based buffer overflow in __vsyslog_internal()
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 3.2% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2024-01-31 · updated 2026-06-17
- Weakness: CWE-122
Description
An off-by-one heap-based buffer overflow was found in the __vsyslog_internal function of the glibc library. This function is called by the syslog and vsyslog functions. This issue occurs when these functions are called with a message bigger than INT_MAX bytes, leading to an incorrect calculation of the buffer size to store the message, resulting in an application crash. This issue affects glibc 2.37 and newer.
Affected products
- Fedoraproject Fedora: 38, 39
- GNU C Library (glibc): from 2.37 before 2.39 — fixed in 2.39
How to fix
Upgrade to a fixed version: GNU C Library (glibc) 2.39. Check the vendor advisory for mitigations.
References
- http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html
- http://seclists.org/fulldisclosure/2024/Feb/3
- https://access.redhat.com/security/cve/CVE-2023-6779
- https://bugzilla.redhat.com/show_bug.cgi?id=2254395
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/D2FIH77VHY3KCRROCXOT6L27WMZXSJ2G/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MWQ6BZJ6CV5UAW4VZSKJ6TO4KIW2KWAQ/
- https://security.gentoo.org/glsa/202402-01
- https://security.netapp.com/advisory/ntap-20240223-0006/
- https://www.openwall.com/lists/oss-security/2024/01/30/6
- https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt
- http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html
- http://seclists.org/fulldisclosure/2024/Feb/3
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