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No exploitation reportedFix available

CVE-2023-6779

No exploitation reported by the sources we read.

  • Published2024-01-31
  • WeaknessCWE-122 · CWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2024-01-3114:15CVE publishedNVD

Versions per branch

NVD
Fedoraproject fedora
BranchAffectedFixed in
38.x= 38no fix published
39.x= 39no fix published
Gnu glibc
BranchAffectedFixed in
2.x≥ 2.37, < 2.392.39

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA8 products

As redhat, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

2 more products in the CVE record.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2024-02-23

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • glibcWolfiall versions · fixed in 2.38-r11
  • glibcUbuntu:24.04:LTSall versions · fixed in 2.39-0ubuntu1
  • glibcMageia:9all versions · fixed in 2.36-52.mga9
  • glibcDebian:14all versions · fixed in 2.37-15
  • glibcDebian:13all versions · fixed in 2.37-15
  • glibcDebian:12all versions · fixed in 2.36-9+deb12u4
  • glibcChainguardall versions · fixed in 2.38-r11
  • glibcBellSoft Hardened Containers:streamfrom 2.37.0-r9 · fixed in 2.37.0-r10

4 more package ranges on OSV.dev

Vendor advisories

  • CVE-2023-6779 Red Hat Product Security

    glibc: off-by-one heap-based buffer overflow in __vsyslog_internal()

  • ICSA-25-162-05 CISA5 known affected

    Siemens SIMATIC S7-1500 CPU family

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) · +2 more

  • SSA-082556 Siemens ProductCERT5 known affected

    SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.5 · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.5 · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.5 · +2 more

Full record on NVD

Fix

  1. Mitigation from the vendor CISA ICSA-25-162-05 · 5 productsLimit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
  2. Mitigation from the vendor CISA ICSA-25-162-05 · 5 productsOnly build and run applications from trusted sources.
  3. Mitigation from the vendor Siemens ProductCERT SSA-082556 · 5 productsLimit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
  4. Mitigation from the vendor Siemens ProductCERT SSA-082556 · 5 productsOnly build and run applications from trusted sources.
  5. No fix available, says the vendor CISA ICSA-25-162-05 · 5 productsCurrently no fix is available
  6. No fix available, says the vendor Siemens ProductCERT SSA-082556 · 5 productsCurrently no fix is available

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CISA-ADPSSVC decisionnone2025-06-13
  • CNACVSS 3.18.2known since 2026-10-23
  • NVDCVSS 3.17.5read 2026-10-23
  • CNAweakness (CWE)CWE-122known since 2026-10-23
  • NVDweakness (CWE)CWE-787read 2026-10-23
  • FIRST EPSSEPSS score3.2 %2026-11-08
  • OSVaffected packages—
  • GitHub Advisoriesadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2024-01-31
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-p5vr-h433-qhqr

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.

Is CVE-2023-6779 actively exploited?

Active exploitation of CVE-2023-6779 has not been confirmed. Its EPSS score was 3.2% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-6779?

CVE-2023-6779 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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