HOMEVULNERABILITIESCVE-2021-33574
CRITICAL

CVE-2021-33574

CWE-416Published: May 25, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-33574 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
gnu1 product(s)
glibc
netapp17 product(s)
cloud backupe-series santricity os controllersolidfire baseboard management controller firmwareh300s firmwareh300sh500s firmwareh500sh700s firmwareh700sh300e firmwareh300eh500e firmware+5
Source: NVD CPE · 22 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (14)

Quick Facts

CVE IDCVE-2021-33574
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-416
CISA KEVNo
Affected4 vendor(s)
PublishedMay 25, 2021

Related CVEs (CWE-416)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-33574 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.