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Vulnerabilities

Vulnerability · CVE-2023-4911

GNU C Library Buffer Overflow Vulnerability

Published Oct 3, 2023 · catalog updated Oct 14, 2026 · GNU GNU C Library (glibc)

Patch now

CVE-2023-4911 is in the CISA known-exploited catalog, due Dec 12, 2023. Confirm GNU GNU C Library (glibc) against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Severity
High7.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
63.77%
Remediation
Remediation guidance
Affected products
cpe canonical/ubuntu linux · cpe fedoraproject/fedora · cpe gnu/glibc · cpe netapp/bootstrap os · cpe netapp/h300s firmware · cpe netapp/h410c firmware

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe canonical/ubuntu linux22.04
  • cpe fedoraproject/fedora37
  • cpe fedoraproject/fedora38
  • cpe gnu/glibcversion unspecified
  • cpe netapp/bootstrap osversion unspecified
  • cpe netapp/h300s firmwareversion unspecified
  • cpe netapp/h410c firmwareversion unspecified
  • cpe redhat/codeready linux builder9.0
  • cpe siemens/simatic s7-1500 cpu 1518-4 pn/dp mfp firmwareversion unspecified
  • cpe siemens/simatic s7-1500 cpu 1518f-4 pn/dp mfp firmwareversion unspecified
  • cpe siemens/simatic s7-1500 tm mfp firmwareversion unspecified
  • cpe siemens/siplus s7-1500 cpu 1518-4 pn/dp mfp firmwareversion unspecified
  • vendor GNU GNU C Libraryversion unspecified
  • vendor GNU GNU C Library (glibc)version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 8.6 Extended Update Supportversion unspecified
  • vendor Red Hat Red Hat Enterprise Linux 9version unspecified
  • vendor Red Hat Red Hat Enterprise Linux 9.0 Extended Update Supportversion unspecified
  • vendor Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8version unspecified

How to fix CVE-2023-4911

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2023-4911 is in the CISA known-exploited catalog, due Dec 12, 2023. Confirm GNU GNU C Library (glibc) against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Compare what you have installed with canonical/ubuntu linux 22.04; redhat/codeready linux builder 9.0. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What should an analyst verify?

CWE-122: Heap-based Buffer Overflow; CWE-787: Out-of-bounds Write. EPSS 63.77%. The CISA KEV listing is the exploitation evidence. A public exploit reference is linked in Sources. That is not the same as confirmed exploitation. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 3, 2023 · Catalog

    Detected

    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.

  2. Nov 21, 2023 · CISA KEV

    Known exploited

    Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

  3. Dec 12, 2023 · CISA KEV

    Remediation due

    Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

  4. Jun 16, 2026 · Catalog

    Updated

    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.

  5. Oct 14, 2026 · NIST NVD

    Updated

    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.

Sources

  • CIRCL Vulnerability LookupVulnerability recordCVE-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 permiss

    vulnerability.circl.lu
  • CISA KEVConfirmed exploitationCVE-2023-4911

    GNU C Library's dynamic loader ld.so contains a buffer overflow vulnerability when processing the GLIBC_TUNABLES environment variable, allowing a local attacker to execute code with elevated privileges.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2023-4911

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2023-4911

    30-day exploitation probability 63.8%

    first.org
  • Exploit DatabasePublic exploit reference52479

    Public archive entry. The exploit body is not stored here.

    exploit-db.com
  • Metasploit ModulesPublic exploit moduleexploit_linux/local/glibc_tunables_priv_esc

    Public module reference (excellent). Module source is not copied into this catalog.

    rapid7.com
  • NIST NVDVulnerability recordCVE-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 permiss

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2023-4911

    GNU C Library's dynamic loader ld.so contains a buffer overflow vulnerability when processing the GLIBC_TUNABLES environment variable, allowing a local attacker to execute code with elevated privileges.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.