CVE-2021-34813
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (4.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a 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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 4.26% probability · 91th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- matrix/olm
- Source
- cve@mitre.org
References
- https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901bPatch, Vendor Advisory
- https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3Release Notes, Vendor Advisory
- https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolmExploit, Patch, Vendor Advisory
- https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901bPatch, Vendor Advisory
- https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3Release Notes, Vendor Advisory
- https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolmExploit, Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.