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ExploitedIn CISA KEVFix available

CVE-2023-4911

Looney Tunables

Exploitation confirmed. First attested on 2023-11-21 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2023-10-03
  • WeaknessCWE-122 · CWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2023-10-0318:15CVE publishedNVD
  2. 2023-11-21Added to the CISA KEV catalogCISA KEV
  3. 2023-11-21Listed as exploited by GCVEGCVE
  4. 2023-11-21Exploitation first reportedCISA KEV
  5. 2025-10-1519:45SSVC exploitation set to activeCISA-ADP
  6. 2026-02-11Exploit-DB entryExploit-DB

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-4911?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-4911?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Redhat codeready linux builder eus
BranchAffectedFixed in
8.6= 8.6no fix published
9.2= 9.2no fix published
9.4= 9.4no fix published
9.6= 9.6no fix published
Redhat codeready linux builder for arm64 eus
BranchAffectedFixed in
8.6= 8.6no fix published
9.2= 9.2_aarch64no fix published
9.4= 9.4_aarch64no fix published
9.6= 9.6_aarch64no fix published
Redhat codeready linux builder for ibm z systems eus
BranchAffectedFixed in
8.6= 8.6no fix published
9.2= 9.2_s390xno fix published
9.4= 9.4_s390xno fix published
9.6= 9.6_s390xno fix published

36 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA11 products

As redhat, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

5 more products in the CVE record.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-02-05

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • glibcWolfiall versions · fixed in 2.38-r5
  • glibcTuxCare:CentOS:8.5all versions · fixed in 2.28-164.el8.tuxcare.els3and 211 other packages
  • glibcRocky Linux:8all versions · fixed in 0:2.28-225.el8_8.6
  • glibcRed Hat:enterprise_linux:9::baseosall versions · fixed in 0:2.34-60.el9_2.7and 59 other packages
  • glibcRed Hat:enterprise_linux:8::baseosall versions · fixed in 0:2.28-225.el8_8.6and 218 other packages
  • glibcopenSUSE:Tumbleweedall versions · fixed in 2.38-4.1
  • glibcopenEuler:22.03-LTS-SP2all versions · fixed in 2.34-137.oe2203sp2
  • glibcopenEuler:22.03-LTS-SP1all versions · fixed in 2.34-137.oe2203sp1

21 more package ranges on OSV.dev

Vendor advisories

  • CVE-2023-4911 Red Hat Product Security4,066 products fixed

    glibc: buffer overflow in ld.so leading to privilege escalation

  • ICSA-25-162-05 CISA5 known affected

    Siemens SIMATIC S7-1500 CPU family

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) · +2 more

  • SSA-082556 Siemens ProductCERT5 known affected

    SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.5 · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.5 · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.5 · +2 more

  • RHSA-2024:0033 Red Hat Product Security6 products fixed

    Red Hat Security Advisory: Red Hat Virtualization Host 4.4.z SP 1 security update

  • RHSA-2023:5476 Red Hat Product Security1,015 products fixed

    Red Hat Security Advisory: glibc security update

  • RHSA-2023:5455 Red Hat Product Security1,017 products fixed

    Red Hat Security Advisory: glibc security update

6 more advisories

Full record on NVD

Fix

  1. CISA’s required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.due 2023-12-12
  2. Vendor fix Red Hat Product Security RHSA-2024:0033 · 6 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/2974891
  3. Vendor fix Red Hat Product Security RHSA-2023:5476 · 1,015 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 For the update to take effect, all services linked to the glibc library must be restarted, or the system rebooted.
  4. Vendor fix Red Hat Product Security RHSA-2023:5453 · 1,014 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
  5. Vendor fix CISA ICSA-23-166-11 · 1 productUpdate to V1.1 or later version
  6. Vendor fix CISA ICSA-23-166-10 · 1 productUpdate to V1.3.0 or later version
  7. Vendor fix Siemens ProductCERT SSA-794697 · 1 productUpdate to V1.1 or later version

Advisories and patches

Detection

read 2026-11-03 22:42 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
EDB-52479
Exploit-DB
Proof-of-concept repositories
20 repositories, unverifiedGreen-Avocado/CVE-2023-4911leesh3288/CVE-2023-4911RickdeJager/CVE-2023-4911xiaoQ1z/CVE-2023-4911silent6trinity/looney-tuneables
PoC-in-GitHub
Metasploit modules
1 moduleexploit/linux/local/glibc_tunables_priv_escrank: excellentModule metadata: Metasploit Framework, © Rapid7, Inc., BSD-3-Clause.
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2023-11-21
Patch Due Date
2023-12-12
Ransomware Use
Unknown
Required Action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published
2023-10-03
Last Modified
2026-10-14
NVD status
Analyzed
GitHub Advisory
GHSA-m77w-6vjw-wh2f

Frequently asked questions

What is 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 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.

Is CVE-2023-4911 actively exploited?

Yes. CVE-2023-4911 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2023-12-12.

What is the CVSS score for CVE-2023-4911?

CVE-2023-4911 has a CVSS v3 base score of 7.8 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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