CVE-2023-6246

HIGH NUCLEI

glibc >=2.36 - Heap-based Buffer Overflow in __vsyslog_internal

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2023-6246. PoCs published by elpe-pinillo, SimoesCTT. A Nuclei detection template is also available.

AI-analyzed exploit summary This exploit leverages a buffer overflow in the `su` command (CVE-2023-6246) to achieve local privilege escalation by manipulating environment variables and crafting a malicious shared library loaded via a fake TTY device.

Description

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.

Exploits (2)

nomisec WORKING POC 7 stars
by elpe-pinillo · poc
https://github.com/elpe-pinillo/CVE-2023-6246

This exploit leverages a buffer overflow in the `su` command (CVE-2023-6246) to achieve local privilege escalation by manipulating environment variables and crafting a malicious shared library loaded via a fake TTY device.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: util-linux su (Fedora 38 default)
No auth needed
Prerequisites: Local access to a vulnerable Fedora 38 system · Ability to compile C code
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC
by SimoesCTT · poc
https://github.com/SimoesCTT/CTT-Vsyslog-Vortex-CVE-2023-6246

This repository contains a functional exploit for CVE-2023-6246, a heap-based buffer overflow in glibc's __vsyslog_internal(). The exploit uses a novel temporal resonance technique to predict heap layout and achieve reliable local privilege escalation to root.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: glibc 2.37, 2.36 (backported)
No auth needed
Prerequisites: Vulnerable glibc version (2.37 or 2.36) · Local access to the target system
devstral-2 · analyzed Apr 10, 2026 Full analysis →

Nuclei Templates (1)

glibc's syslog - Local Privilege Escalation
HIGHby gy741

Scores

CVSS v3 8.4
EPSS 0.0479
EPSS Percentile 90.8%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-122 CWE-787
Status published
Products (9)
None/glibc 2.39
Fedora/Fedora
fedoraproject/fedora 38
fedoraproject/fedora 39
gnu/glibc 2.36 - 2.39
Red Hat/Red Hat Enterprise Linux 6
Red Hat/Red Hat Enterprise Linux 7
Red Hat/Red Hat Enterprise Linux 8
Red Hat/Red Hat Enterprise Linux 9
Published Jan 31, 2024
Tracked Since Feb 18, 2026