Use After Free in GNU Glibc
CVE-2023-4806
A flaw has been identified in glibc. In an extremely rare situation, the getaddrinfo function may access memory that has been freed, resulting in an application crash. This issue is only exploitable when a NSS module implements only the _nss_*_gethostbyname2_r and _nss_*_getcanonname_r hooks without implementing the _nss_*_gethostbyname3_r hook. The resolved name should return a large number of IPv6 and IPv4, and the call to the getaddrinfo function should have the AF_INET6 address family with AI_CANONNAME, AI_ALL and AI_V4MAPPED as flags.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.016 (75.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 75.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000
Affected products
- GNU Glibc — versions 2.33
- Fedoraproject Fedora — versions 37, 38, 39
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8 — versions 0:2.28-225.el8_8.6
- Red Hat Enterprise Linux 8.6 Extended Update Support — versions 0:2.28-189.8.el8_6
- Red Hat Enterprise Linux 9 — versions 0:2.34-100.el9, 0:2.34-60.el9_2.7
- Red Hat Virtualization 4 For Enterprise Linux 8 — versions 0:2.28-189.8.el8_6
- Red Hat Codeready Linux Builder Eus — versions 9.2
- Red Hat Codeready Linux Builder Eus For Power Little Endian — versions 9.0_ppc64le
Weakness classification (CWE)
Public proof-of-concept exploits
References
- RHBA-2024:2413 (vendor-advisory)
- RHSA-2023:5453 (vendor-advisory, Third Party Advisory)
- RHSA-2023:5455 (vendor-advisory, Third Party Advisory)
- RHSA-2023:7409 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2023-4806 (Third Party Advisory, vdb-entry)
- RHBZ#2237782 (issue-tracking, Third Party Advisory, Issue Tracking)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2023-4806?
- CVE-2023-4806 is a medium-severity vulnerability in GNU Glibc, classified under Use After Free. CVSS score: 5.9/10. Published 2023-09-18.
- How severe is CVE-2023-4806?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2023-4806 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.