CVE-2023-4806

2023-09-1800:00:00

ubuntu.com

glibc

getaddrinfo

memory access

application crash

nss module

ipv6

ipv4

af_inet6

ai_canonname

ai_all

ai_v4mapped

6.5 Medium

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

40.3%

JSON

A 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.

Bugs

<https://sourceware.org/bugzilla/show_bug.cgi?id=30843>

Notes

Author	Note
	Priority reason: No known NSS modules expose the vulnerability
mdeslaur	This is only an issue when using an NSS module with a very specific behaviour. There are no known NSS modules which are implemented this way. The fix for this issue introduced a leak, identified as CVE-2023-5156 which was later fixed with a subsequent commit. Older releases require backporting a dozen refactoring commits.
ccdm94	One of the refactoring commits needed to fix this issue is also the fix for CVE-2023-4813.

OSVersionArchitecturePackageVersionFilename
ubuntu14.04noarcheglibc< anyUNKNOWN
ubuntu18.04noarchglibc< 2.27-3ubuntu1.6+esm1) Available with Ubuntu Pro or Ubuntu Pro (Infra-onlyUNKNOWN
ubuntu20.04noarchglibc< 2.31-0ubuntu9.14UNKNOWN
ubuntu22.04noarchglibc< 2.35-0ubuntu3.5UNKNOWN
ubuntu23.04noarchglibc< 2.37-0ubuntu2.2UNKNOWN
ubuntu23.10noarchglibc< 2.38-1ubuntu5UNKNOWN
ubuntu24.04noarchglibc< 2.38-1ubuntu5UNKNOWN
ubuntu16.04noarchglibc< 2.23-0ubuntu11.3+esm5) Available with Ubuntu Pro or Ubuntu Pro (Infra-onlyUNKNOWN

OS	Version	Architecture	Package	Version	Filename
ubuntu	14.04	noarch	eglibc	< any	UNKNOWN
ubuntu	18.04	noarch	glibc	< 2.27-3ubuntu1.6+esm1) Available with Ubuntu Pro or Ubuntu Pro (Infra-only	UNKNOWN
ubuntu	20.04	noarch	glibc	< 2.31-0ubuntu9.14	UNKNOWN
ubuntu	22.04	noarch	glibc	< 2.35-0ubuntu3.5	UNKNOWN
ubuntu	23.04	noarch	glibc	< 2.37-0ubuntu2.2	UNKNOWN
ubuntu	23.10	noarch	glibc	< 2.38-1ubuntu5	UNKNOWN
ubuntu	24.04	noarch	glibc	< 2.38-1ubuntu5	UNKNOWN
ubuntu	16.04	noarch	glibc	< 2.23-0ubuntu11.3+esm5) Available with Ubuntu Pro or Ubuntu Pro (Infra-only	UNKNOWN