CVE-2021-33574
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)
02 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)
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 3.52% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 89.0% of scored records. A rank, not a probability.
- NVD base score
- 9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-10-14.
- Red Hat severity
- Low. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-05-25 00:00Z5 YR AGO
- Last updated
- 2026-10-14 11:44Z15 DAYS AGO
- Reserved
- 2021-05-25
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-416Use After FreeVariant
- Data version
- 5.2
- Document digest
- 57740b12978777176d46bf263d362057c536ba1a11dcb18d059aed97ab0a63bd
05 Affected products
06 References
- sourceware.orghttps://sourceware.org/bugzilla/show_bug.cgi?id=27896
- sourceware.orghttps://sourceware.org/bugzilla/show_bug.cgi?id=27896#c1
- lists.fedoraproject.orgFEDORA-2021-7ddb8b0537https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RBUUWUGXVILQXVWEOU7N42ICHPJNAEUP/
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20210629-0005/
- security.gentoo.orgGLSA-202107-07https://security.gentoo.org/glsa/202107-07
- lists.fedoraproject.orgFEDORA-2021-f29b4643c7https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJYYIMDDYOHTP2PORLABTOHYQYYREZDD/
- lists.debian.org[debian-lts-announce] 20221017 [SECURITY] [DLA 3152-1] glibc security updatehttps://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-831302.html
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-398330.html
07 Fixed in
AlmaLinux 8
- compat-libpthread-nonshared Fixed in 2.28-164.el8
- glibc-benchtests Fixed in 2.28-164.el8
- glibc-nss-devel Fixed in 2.28-164.el8
- glibc-static Fixed in 2.28-164.el8
- glibc-utils Fixed in 2.28-164.el8
- nss_hesiod Fixed in 2.28-164.el8
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Arch Linux
- glibc Fixed in 2.34-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
CloudLinux 8
- compat-libpthread-nonshared Fixed in 2.28-164.el8
- glibc-benchtests Fixed in 2.28-164.el8
- glibc-nss-devel Fixed in 2.28-164.el8
- glibc-static Fixed in 2.28-164.el8
- glibc-utils Fixed in 2.28-164.el8
- nss_hesiod Fixed in 2.28-164.el8
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- glibc Fixed in 2.32-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- glibc Fixed in 2.32-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- glibc Fixed in 2.32-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- eglibc No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- glibc No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- glibc No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- glibc No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.