CVE-2021-33574

Name: CVE-2021-33574
Creator: NVD / NIST
Published: 2021-05-25T22:15:10.41+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.90%

Last modified Jun 17, 2026

CVE-2021-33574 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. The mq_notify function in the GNU C Library (aka glibc) versions 2.32 and 2.33 has a use-after-free. It may use the notification thread attributes object (passed through its struct sigevent parameter) after it has been freed by the caller, leading to a denial of service (application crash) or possibly unspecified other impact.. EPSS estimates a 2.90% chance of exploitation in the next 30 days.

Description

The mq_notify function in the GNU C Library (aka glibc) versions 2.32 and 2.33 has a use-after-free. It may use the notification thread attributes object (passed through its struct sigevent parameter) after it has been freed by the caller, leading to a denial of service (application crash) or possibly unspecified other impact.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.90%

85.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Gnu	Glibc	2.32
Gnu	Glibc	2.33
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Netapp	Cloud Backup	All versions
Netapp	E-Series Santricity Os Controller	>= 11.0, <= 11.70.1
Netapp	Solidfire Baseboard Management Controller Firmware	All versions
Netapp	H300s Firmware	All versions
Netapp	H500s Firmware	All versions
Netapp	H700s Firmware	All versions
Netapp	H300e Firmware	All versions
Netapp	H500e Firmware	All versions
Netapp	H700e Firmware	All versions
Netapp	H410s Firmware	All versions
Debian	Debian Linux	10.0

References

https://lists.debian.org/debian-lts-announce/2022/10/msg00021.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJYYIMDDYOHTP2PORLABTOHYQYYREZDD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RBUUWUGXVILQXVWEOU7N42ICHPJNAEUP/
https://security.gentoo.org/glsa/202107-07Third Party Advisory
https://security.netapp.com/advisory/ntap-20210629-0005/Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896Exploit, Issue Tracking, Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896#c1Issue Tracking
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJYYIMDDYOHTP2PORLABTOHYQYYREZDD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RBUUWUGXVILQXVWEOU7N42ICHPJNAEUP/
https://security.gentoo.org/glsa/202107-07Third Party Advisory
https://security.netapp.com/advisory/ntap-20210629-0005/Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896Exploit, Issue Tracking, Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896#c1Issue Tracking

Timeline

Published: May 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33574?

How severe is CVE-2021-33574?

CVE-2021-33574 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.90% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33574?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-33574?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST