CVE-2023-4527

Publication date 18 September 2023

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in glibc. When the getaddrinfo function is called with the AF_UNSPEC address family and the system is configured with no-aaaa mode via /etc/resolv.conf, a DNS response via TCP larger than 2048 bytes can potentially disclose stack contents through the function returned address data, and may cause a crash.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
glibc	24.04 LTS noble	Fixed 2.38-1ubuntu5
	23.10 mantic	Fixed 2.38-1ubuntu5
	23.04 lunar	Fixed 2.37-0ubuntu2.1
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Ignored end of standard support
eglibc	24.04 LTS noble	Not in release
	23.10 mantic	Not in release
	23.04 lunar	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not affected

Notes

mdeslaur

no-aaaa was introduced in 2.36 by: https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=f282cdbe7f436c75864e5640a409a10485e9abb2 system needs to be configured in no-aaaa mode in resolv.conf

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
glibc	Upstream: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=4ea972b7edd7e36610e8cde18bf7a8149d7bac4f Upstream: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b7529346025a130fee483d42178b5c118da971bb Upstream: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b25508dd774b617f99419bdc3cf2ace4560cd2d6

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H