CVE-2021-34813

Public Exploit

Description

Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.

Category

9.8
CVSS
Severity: Critical
CVSS 3.1 •
CVSS 2.0 •
EPSS 4.46% Top 15%
Vendor Advisory matrix.org Vendor Advisory matrix.org Vendor Advisory matrix.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm exploit patch vendor advisory
https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3 release notes vendor advisory
https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b patch vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-34813?
CVE-2021-34813 has been scored as a critical severity vulnerability.
How to fix CVE-2021-34813?
To fix CVE-2021-34813, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-34813 being actively exploited in the wild?
It is possible that CVE-2021-34813 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~4% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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