Glibc: off-by-one heap-based buffer overflow in __vsyslog_internal()
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | glibc | — | 2.39 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | Not affected | CNA |
| Fedora | Fedora | — | — | No fix listed | CNA |
- glibc Vendor— Affected — Fixed in 2.39 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — Not affected CNA
- Fedora VendorFedora Affected — Fixed in — No fix listed CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:* | 2.37 to before 2.39 | Vulnerable | GNU |
| cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* | 38 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:* | 39 | Vulnerable | Fedoraproject |
- cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:* Versions 2.37 to before 2.39 Vulnerable ·GNU
- cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* Versions 38 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:* Versions 39 Vulnerable ·Fedoraproject
Remediation
- Fix · CNA glibc Fixed in 2.39
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2023-6779
- 2026-10-03 Alias added: GHSA-p5vr-h433-qhqr
References
Exploit 3
Advisory 4
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Sources
- CVE-2023-6779 · CVE Program
- CVE-2023-6779 · NVD
- FIRST EPSS
- GHSA-p5vr-h433-qhqr · GitHub Advisory Database · CC BY 4.0
- CVE-2023-6779 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences