CVE-2021-34981: Linux Kernel Bluetooth CMTP Module Double Free Privilege Escalation Vulnerability
Vulnerability summary
CVE-2021-34981 is a high (CVSS 7.5) Double Free vulnerability in linux kernel. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.8% of scored vulnerabilities.
Not severe (CVSS 7.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 19 · Duplicates 1 · Related 19Timeline
- 07-05-2024PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
6 scores · 4 sources · 2 versions- OSV · DebianEcosystem advisory · calculated6.7MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- NVDNIST6.7MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
- NVDNIST7.5HighCVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
10%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.20% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, administrative account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu64 products
- linuxAll versions (No fix recorded)
- linux-awsAll versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
- linux-aws-5.3All versions (No fix recorded)
Linux2 products
- kernel4.15.0-118-generic
- linux_kernel< 5.10.42
Debian1 product
- linux< 5.10.46-1
3 vendors · 67 products
