CVE-2023-4911
Glibc: buffer overflow in ld.so leading to privilege escalation
Exploited in the wild. In CISA KEV since 2023‑11‑21. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Listed as exploited in the wild since 2023-11-21.
US federal agencies must remediate by 2023-12-12.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Public exploits
5 sources with a proof of concept or module.
Exploit links, PoCs and Metasploit modules after sign-in- EPSS
81% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
A public exploit existed 67 days before the patch.
- OpenVAS check added
- Patch availableworkaround available, record updated
- Public exploit / PoCsource: othernuclei check added
- Added to CISA KEV
- Publishedweakness classified, att&ck mapped
Affected products
- Red Hat VirtualizationOperating Systems / linux-distro
- Red Hat Enterprise Linux 8Operating Systems / linux-distro
- Red Hat Enterprise Linux 8.6 Extended Update SupportOperating Systems / linux-distro
- Red Hat Enterprise Linux 9.0 Extended Update SupportOperating Systems / linux-distro
- Red Hat Virtualization 4 for Red Hat Enterprise Linux 8Operating Systems / linux-distro
- codeready linux builderOperating Systems / linux-distro
- codeready linux builder eusOperating Systems / linux-distro
- codeready linux builder for arm64Operating Systems / linux-distro
And 34 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored 7.8 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
References in the record
- sourceware.org/git/?p=glibc.git;a=commit;h=1056e5b4c3f2d90ed2b4a55f96add28da2f4c8fa&
- access.redhat.com/security/cve/CVE-2023-4911&
- security-tracker.debian.org/tracker/CVE-2023-4911&
And 285 more references. See all after sign-in
In the news
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