CVE & CISA-KEV Catalog

CVE-2021-34981

MEDIUM
6.7
CVSS v3
NVD

Description

Linux Kernel Bluetooth CMTP Module Double Free Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the CMTP module. The issue results from the lack of validating the existence of an object prior to performing further free operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the kernel. Was ZDI-CAN-11977.

How to fix

Remediation Available
linuxDebian
Fixed in:5.10.46-1CVE-2021-34981
Fixed in:5.10.46-1CVE-2021-34981
Fixed in:5.10.46-1CVE-2021-34981
Fixed in:5.10.46-1CVE-2021-34981

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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

Exploit Intelligence

0.20%probability of exploitation in 30 days
10thpercentile

Low risk: more likely to be exploited than 10% of all known CVEs.

References

Third-Party Advisory1

Related Vulnerabilities

Other CWE-415 vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2023-25136Medium6.590%-Fix
CVE-2018-0101Critical10.087%-Fix
CVE-2003-0545Critical9.885%-Fix
CVE-2019-3829Medium5.359%-Fix
CVE-2026-33824Critical9.856%-Fix
CVE-2021-3407Medium5.550%-Fix
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-08-14.