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🛡️ CVE-2023-4911 on Ubuntu — glibc

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

Distribution advisory

This page covers CVE-2023-4911 as tracked by Ubuntu, for the package glibc. The fix is available in version 2.38-1ubuntu6; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

UBUNTU-CVE-2023-4911 is classified as CWE-122: Heap-based Buffer Overflow. A write past the end of a heap allocation corrupts allocator metadata or neighbouring objects.

Affected software

UBUNTU-CVE-2023-4911 is recorded against 1 package.

  • glibc (fixed in 2.38-1ubuntu6)

Timeline and source

Published on 3 October 2023 and last revised on 22 April 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.qualys.com (Report)
ubuntu.com (Advisory)
www.cve.org (Report)
www.cisa.gov (Report)

Other advisories for this package

glibc has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-122: Heap-based Buffer Overflow) in other software:

CVE-2023-4911 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2023-10-03
Updated 2026-08-20
Modified 2026-04-22
Fix URL N/A

Affected Packages

Software From version Fixed in
glibc — 2.38-1ubuntu6

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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