CVE-2023-6779
Glibc: off-by-one heap-based buffer overflow in __vsyslog_internal()
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.2
Glibc: off-by-one heap-based buffer overflow in __vsyslog_internal()
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.
- Record
CVE-2023-6779- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2023-58991
8.2
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.
- Record
EUVD-2023-58991- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p5vr-h433-qhqr
8.2
An off-by-one heap-based buffer overflow was found in the __vsyslog_internal function of the...
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.
- Record
GHSA-p5vr-h433-qhqr- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-122, CWE-787
- Updated
- 2026-11-02
NVD
8.2
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.
- Record
CVE-2023-6779- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-122, CWE-787
- Updated
- 2026-11-02
OSVAZL-34736
7.5
CVE-2023-6779 affecting package glibc for versions less than 2.38-6
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.
- Record
AZL-34736- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVBELL-CVE-2023-6779
7.5
- Record
BELL-CVE-2023-6779- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSV
8.2
Glibc: off-by-one heap-based buffer overflow in __vsyslog_internal()
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.
- Record
CVE-2023-6779- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2023-6779
7.5
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.
- Record
DEBIAN-CVE-2023-6779- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2023-6779
7.5
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.
- Record
UBUNTU-CVE-2023-6779- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-02
OSVMGASA-2024-0026 No score
Updated glibc packages fix security vulnerabilities
The updated packages fix security vulnerabilities: 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. (CVE-2023-6246) 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. (CVE-2023-6779) An integer 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 very long message, leading to an incorrect calculation of the buffer size to store the message, resulting in undefined behavior. (CVE-2023-6780)
- Record
MGASA-2024-0026- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
glibcAzure Linux:3 |
before 2.38-6 | 2.38-6 |
glibcAlpaquita:23 |
2.37.0-r9 up to 2.37.0-r10 | 2.37.0-r10 |
glibcAlpaquita:stream |
2.37.0-r9 up to 2.37.0-r10 | 2.37.0-r10 |
glibcBellSoft Hardened Containers:23 |
2.37.0-r9 up to 2.37.0-r10 | 2.37.0-r10 |
glibcBellSoft Hardened Containers:stream |
2.37.0-r9 up to 2.37.0-r10 | 2.37.0-r10 |
glibcDebian:12 |
before 2.36-9+deb12u4, plus listed versions 2.36-92.36-9+deb12u12.36-9+deb12u22.36-9+deb12u3 |
2.36-9+deb12u4 |
glibcDebian:13 |
before 2.37-15 | 2.37-15 |
glibcDebian:14 |
before 2.37-15 | 2.37-15 |
glibcMageia:9 |
before 2.36-52.mga9 | 2.36-52.mga9 |
glibcUbuntu:24.04:LTS |
before 2.39-0ubuntu1, plus listed versions 2.38-1ubuntu62.38-3ubuntu1 |
2.39-0ubuntu1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-6779 is a high vulnerability (CVSS 8.2) in Gnu Glibc, published January 30, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.15%, the 87th percentile. Fixed in glibc 2.38-6.
References
packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html
seclists.org/fulldisclosure/2024/Feb/3
access.redhat.com/security/cve/CVE-2023-6779
bugzilla.redhat.com/show_bug.cgi?id=2254395
lists.fedoraproject.org/archives/list/[email protected]/message/D2FIH77VHY3KCRROCXOT6L27WMZXSJ2G
lists.fedoraproject.org/archives/list/[email protected]/message/MWQ6BZJ6CV5UAW4VZSKJ6TO4KIW2KWAQ
Show 20 moreShow less
security.gentoo.org/glsa/202402-01
openwall.com/lists/oss-security/2024/01/30/6
qualys.com/2024/01/30/cve-2023-6246/syslog.txt
security.netapp.com/advisory/ntap-20240223-0006
cert-portal.siemens.com/productcert/html/ssa-082556.html
nvd.nist.gov/vuln/detail/CVE-2023-6779
github.com/advisories/GHSA-p5vr-h433-qhqr
docs.bell-sw.com/security/cves/CVE-2023-6779
docs.bell-sw.com/security/advisories/BELL-SA-2024-9
access.redhat.com/downloads/content/package-browser
packages.fedoraproject.org
github.com/CVEProject/cvelistV5/tree/main/cves/2023/6xxx/CVE-2023-6779.json
security-tracker.debian.org/tracker/CVE-2023-6779
advisories.mageia.org/MGASA-2024-0026.html
bugs.mageia.org/show_bug.cgi?id=32796
security-tracker.debian.org/tracker/DSA-5611-1
bodhi.fedoraproject.org/updates/FEDORA-2024-aec80d6e8a
ubuntu.com/security/CVE-2023-6779
ubuntu.com/security/notices/USN-6620-1
cve.org/CVERecord?id=CVE-2023-6779