CVE-2021-1048 — Android Kernel Use-After-Free Vulnerability

In ep_loop_check_proc of eventpoll.c, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Andr

01What is this vulnerability?

In ep_loop_check_proc of eventpoll.c, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-204573007References: Upstream kernel

02Affected products

Vendor	Product	Versions
n	a / Android	Android kernel

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2022-05-23. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2021-12-15T18:05:35.000Z
• Last modified: 2025-10-21T23:15:50.344Z
• Added to CISA KEV: 2022-05-23
• BOD 22-01 due: 2022-06-13

09References

• source.android.com — https://source.android.com/security/bulletin/2021-11-01