CVE-2021-0920

Advisory lineage Upstream: 0 Downstream: 54
Analyzed
Published: 15 Dec 2021, 18:05
Last modified:21 Oct 2025, 23:15

Vulnerability Summary

Overall Risk (default)
medium
28/100
CVSS Score
6.9 MEDIUM
v2.0 (nvd)
EPSS Score
0.93% LOW
1% probability +0.03%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

15 Dec 2021, 18:05
Published
Vulnerability first disclosed
23 May 2022, 00:00
Added to CISA KEV
Android Kernel Race Condition Vulnerability
13 Jun 2022, 00:00
CISA Remediation Due
Apply updates per vendor instructions.
21 Oct 2025, 23:15
Last Modified
Vulnerability information updated

Description

In unix_scm_to_skb of af_unix.c, there is a possible use after free bug due to a race condition. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-196926917References: Upstream kernel

CVSS Metrics

  • v3.1•MEDIUM•Score: 6.4CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
  • v2.0•MEDIUM•Score: 6.9AV:L/AC:M/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 0.93%• Percentile: 77%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • debian•debian_linux

    9.0

  • google•android

    na

  • linux•linux_kernel

    ≤ 5.13 | 5.14:rc1 | 5.14:rc2 | 5.14:rc3

References (3)