CVE-2021-27645

Publication date 24 February 2021

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
eglibc	24.04 LTS noble	Not in release
	23.10 mantic	Not in release
	23.04 lunar	Not in release
	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	21.10 impish	Not in release
	21.04 hirsute	Not in release
	20.10 groovy	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
glibc	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.10 groovy	Ignored
	20.04 LTS focal	Fixed 2.31-0ubuntu9.7
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release

Notes

mdeslaur

introduced in 2.29 by: https://sourceware.org/git/?p=glibc.git;a=commit;h=745664bd798ec8fd50438605948eea594179fba1 introduced in 2.28-1 debian packaging by: https://salsa.debian.org/glibc-team/glibc/-/commit/aea56157b456d4d9bef337d0149e952a41a7d919

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/?p=glibc.git;a=commit;h=dca565886b5e8bd7966e15f0ca42ee5cff686673

Severity score breakdown

Parameter	Value
Base score	2.5 · Low
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	Low
Vector	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L