CVE-2023-6779: glibc Heap Overflow — Exploit

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.

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CVSS v3.1 Score

8.2

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Weakness Type (CWE)

CWE-122 CWE-122

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
gnu	glibc	2.37 — 2.39
fedoraproject	fedora	All
fedoraproject	fedora	All

References

Exploits

http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html http://seclists.org/fulldisclosure/2024/Feb/3 https://www.openwall.com/lists/oss-security/2024/01/30/6 http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html http://seclists.org/fulldisclosure/2024/Feb/3 https://www.openwall.com/lists/oss-security/2024/01/30/6

Other References

https://access.redhat.com/security/cve/CVE-2023-6779 https://bugzilla.redhat.com/show_bug.cgi?id=2254395 https://lists.fedoraproject.org/archives/list/[email protected]/message/D2FIH77VHY3KCRROCXOT6L27WMZXSJ2G/ https://lists.fedoraproject.org/archives/list/[email protected]/message/MWQ6BZJ6CV5UAW4VZSKJ6TO4KIW2KWAQ/ https://security.gentoo.org/glsa/202402-01 https://security.netapp.com/advisory/ntap-20240223-0006/ https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt https://access.redhat.com/security/cve/CVE-2023-6779 https://bugzilla.redhat.com/show_bug.cgi?id=2254395 https://lists.fedoraproject.org/archives/list/[email protected]/message/D2FIH77VHY3KCRROCXOT6L27WMZXSJ2G/

Frequently Asked Questions

What is CVE-2023-6779? +

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. It has a CVSS v3.1 base score of 8.2 (HIGH).

How severe is CVE-2023-6779? +

CVE-2023-6779 has a CVSS v3.1 score of 8.2 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-6779? +

CVE-2023-6779 affects products from fedoraproject, gnu, specifically: fedora, glibc. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-6779? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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