CVE-2023-4911
A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue…
Browse: All 2023 CVEs · All vendors
- CVSS score
- 7.8 High
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- CISA KEV
- Yes — actively exploited (added 2023-11-21, remediation due 2023-12-12)
- Weakness (CWE)
- CWE-122, CWE-787
- Published
- 2023-10-03
- Last modified
- 2026-06-17
- NVD status
- Analyzed
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.
Affected products
- netapp bootstrap os
- siemens simatic s7-1500 cpu 1518-4 pn\/dp mfp firmware
- siemens simatic s7-1500 cpu 1518f-4 pn\/dp mfp firmware
- siemens siplus s7-1500 cpu 1518-4 pn\/dp mfp firmware
- siemens simatic s7-1500 tm mfp firmware
- gnu glibc
- fedoraproject fedora
- redhat codeready linux builder
- redhat codeready linux builder eus
- redhat codeready linux builder for arm64
- redhat codeready linux builder for arm64 eus
- redhat codeready linux builder for ibm z systems
Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.
Required action (CISA)
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. Federal remediation deadline: 2023-12-12.
How to prioritize this
This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score.
References
- https://access.redhat.com/errata/RHSA-2023:5453
- https://access.redhat.com/errata/RHSA-2023:5454
- https://access.redhat.com/errata/RHSA-2023:5455
- https://access.redhat.com/errata/RHSA-2023:5476
- https://access.redhat.com/errata/RHSA-2024:0033
- https://access.redhat.com/security/cve/CVE-2023-4911
- https://bugzilla.redhat.com/show_bug.cgi?id=2238352
- https://www.qualys.com/2023/10/03/cve-2023-4911/looney-tunables-local-privilege-escalation-glibc-ld-so.txt
FAQ
Is CVE-2023-4911 actively exploited?
Yes. CISA added CVE-2023-4911 to its Known Exploited Vulnerabilities (KEV) catalog on 2023-11-21, with a federal remediation deadline of 2023-12-12. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.
What is the CVSS score of CVE-2023-4911?
CVE-2023-4911 has a CVSS base score of 7.8 (High). Its vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Related vulnerabilities
- CVE-2026-24061 — GNU InetUtils
- CVE-2014-6278 — GNU GNU Bash
- CVE-2014-6271 — GNU Bourne-Again Shell (Bash)
- CVE-2014-7169 — GNU Bourne-Again Shell (Bash)
- CVE-2026-53362 — Linux Kernel
- CVE-2009-3459 — Adobe Acrobat and Reader
Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.
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