CVE-2021-38604

Publication date 12 August 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

In librt in the GNU C Library (aka glibc) through 2.34, sysdeps/unix/sysv/linux/mq_notify.c mishandles certain NOTIFY_REMOVED data, leading to a NULL pointer dereference. NOTE: this vulnerability was introduced as a side effect of the CVE-2021-33574 fix.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
eglibc	22.04 LTS jammy	Not in release
	21.10 impish	Not in release
	21.04 hirsute	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	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Ignored end of life
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release

Notes

sbeattie

21.04 and earlier are not affected due to the fix for CVE-2021-33574 having not been introduced yet.

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=commitdiff;h=4cc79c217744743077bf7a0ec5e0a4318f1e6641 Upstream: https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=b805aebd42364fe696e417808a700fdb9800c9e8

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Other references

https://www.cve.org/CVERecord?id=CVE-2021-38604