What’s Vulnerable › Vulnerabilities

CVE-2023-6246: Glibc: heap-based buffer overflow in __vsyslog_internal()

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.8% 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

A 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 the openlog function was not called, or called with the ident argument set to NULL, and the program name (the basename of argv[0]) is bigger than 1024 bytes, resulting in an application crash or local privilege escalation. This issue affects glibc 2.36 and newer.

Affected products

• Fedoraproject Fedora: 38, 39
• GNU C Library (glibc): from 2.36 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/176931/glibc-qsort-Out-Of-Bounds-Read-Write.html
• http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html
• http://seclists.org/fulldisclosure/2024/Feb/3
• http://seclists.org/fulldisclosure/2024/Feb/5
• https://access.redhat.com/security/cve/CVE-2023-6246
• https://bugzilla.redhat.com/show_bug.cgi?id=2249053
• 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-20240216-0007/
• https://www.openwall.com/lists/oss-security/2024/01/30/6
• https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt

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