CVE-2023-6780 | Glibc: integer overflow in __vsyslog_internal()

Exp

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. This issue affects glibc 2.37 and newer.

Published: 2024-01-31 Last update: 2026-05-12 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-6780 is rated Exploit Available (50.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.22%). 3 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-6780

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-6780

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 1.68% 0.22% -1.46%
2 2025-11-18 0.23% 1.68% +1.44%
3 2025-11-08 — 0.23% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-6780

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-6780

GitHub Security Advisory for CVE-2023-6780

GHSA-jjr8-97p7-vmmg · Severity: medium — An integer overflow was found in the __vsyslog_internal function of the glibc library. This...

OS Trackers for CVE-2023-6780

vendor priority summary link
debian unimportant CVE-2023-6780 unimportant priority: Debian including 1 source packages (glibc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-6780
gentoo high CVE-2023-6780: 1 GLSA(s) (202402-01), 1 atom(s) (sys-libs/glibc); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-6780
redhat low — https://access.redhat.com/security/cve/CVE-2023-6780
suse high CVE-2023-6780 severity important: SUSE including 73 source package names (glibc, glibc-2.38-150600.12.1, …), 483 product×package rows across 55 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7.1, … (55 product lines)): Known Not Affected 428, Fixed 55. https://www.suse.com/security/cve/CVE-2023-6780/
ubuntu medium CVE-2023-6780 medium priority: Ubuntu including 2 source packages (eglibc, glibc), 16 status rows across 8 suites (bionic, focal, jammy, mantic, noble, trusty, upstream, xenial): DNE 7, not-affected 5, released 3, needs-triage 1. https://ubuntu.com/security/CVE-2023-6780

Affected software / configurations for CVE-2023-6780

Vendor Product Version Raw CPE
gnu glibc >= 2.37, < 2.39 cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
fedoraproject fedora 39 cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*

References for CVE-2023-6780

URL Tags
http://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html Exploit Third Party Advisory VDB Entry
http://seclists.org/fulldisclosure/2024/Feb/3 Exploit Mailing List Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-6780 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2254396 Issue Tracking
https://lists.fedoraproject.org/archives/list/[email protected]/message/D2FIH77VHY3KCRROCXOT6L27WMZXSJ2G/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/MWQ6BZJ6CV5UAW4VZSKJ6TO4KIW2KWAQ/ Mailing List
https://security.gentoo.org/glsa/202402-01 Third Party Advisory
https://www.openwall.com/lists/oss-security/2024/01/30/6 Exploit Mailing List
https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt Third Party Advisory
https://security.netapp.com/advisory/ntap-20250207-0010/
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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