CVE-2023-6246 | Glibc: heap-based buffer overflow in __vsyslog_internal()

Exp

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. This issue affects glibc 2.36 and newer.

Published: 2024-01-31 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-6246 is rated High Exploit Risk (75.4/100): CVSS High severity, with high exploitation likelihood (EPSS 4.79%, 91th percentile). 6 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-2023-6246

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— 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-2023-6246

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 2026-06-15 26.96% 4.79% -22.17%
2 2026-05-31 25.48% 26.96% +1.48%
3 2026-04-11 — 25.48% —

Full EPSS history (39 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-6246

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.4 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.5 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2023-6246

GitHub Security Advisory for CVE-2023-6246

GHSA-p6rw-gvvh-q8v4 · Severity: high — A heap-based buffer overflow was found in the __vsyslog_internal function of the glibc library....

OS Trackers for CVE-2023-6246

vendor priority summary link
debian unimportant CVE-2023-6246 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-2023-6246
gentoo high CVE-2023-6246: 1 GLSA(s) (202402-01), 1 atom(s) (sys-libs/glibc); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-6246
redhat high — https://access.redhat.com/security/cve/CVE-2023-6246
suse high CVE-2023-6246 severity important: SUSE including 86 source package names (glibc, glibc-2.38-150600.12.1, …), 496 product×package rows across 56 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7.1, … (56 product lines)): Known Not Affected 428, Fixed 68. https://www.suse.com/security/cve/CVE-2023-6246/
ubuntu medium CVE-2023-6246 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-2023-6246

Affected software / configurations for CVE-2023-6246

Vendor Product Version Raw CPE
gnu glibc >= 2.36, < 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-2023-6246

URL Tags
http://packetstormsecurity.com/files/176931/glibc-qsort-Out-Of-Bounds-Read-Write.html Exploit Third Party Advisory VDB Entry
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 Third Party Advisory
http://seclists.org/fulldisclosure/2024/Feb/5 Exploit Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-6246 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2249053 Issue Tracking Third Party Advisory
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://security.netapp.com/advisory/ntap-20240216-0007/
https://www.openwall.com/lists/oss-security/2024/01/30/6 Exploit Mailing List Third Party Advisory
https://www.qualys.com/2024/01/30/cve-2023-6246/syslog.txt Exploit Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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