DescriptionA flaw was found 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
glibc (PTS)buster2.28-10+deb10u1vulnerable
buster (security)2.28-10+deb10u2vulnerable
bullseye (security)2.31-13+deb11u7vulnerable
bookworm, bookworm (security)2.36-9+deb12u4fixed
trixie, sid2.37-15fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs


[bullseye] - glibc <no-dsa> (Minor issue)
[buster] - glibc <no-dsa> (Minor issue);h=973fe93a5675c42798b2161c6f29c01b0e243994
When fixing this issue in older releases make sure to not open CVE-2023-5156.

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