PT-2021-4263 · Unknown+4 · Matrix Libolm+4

Denis Kasak · Published 2021-06-16 · Updated 2021-12-15 · CVE-2021-34813

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Matrix libolm versions prior to 3.2.3

Description The issue is related to a stack-based buffer overflow in the olm pk decrypt function, which can be triggered by a malicious Matrix homeserver. This could potentially allow remote code execution in nonstandard build configurations. The vulnerability is also described as a buffer overflow issue in the Double Ratchet Libolm implementation, which could enable a remote attacker to access confidential data, compromise its integrity, and cause a denial of service.

Recommendations For Matrix libolm versions prior to 3.2.3, update to version 3.2.3 or later to resolve the issue. As a temporary workaround, consider restricting interactions with potentially malicious Matrix homeservers to minimize the risk of exploitation.

Exploit

Fix

RCE

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

ALT-PU-2021-2798

BDU:2021-04871

CVE-2021-34813

USN-5194-1

Affected Products

Alt Linux

Debian

Linuxmint

Matrix Libolm

Ubuntu

References · 13

• 🔥 https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm · Exploit
• https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-34813 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-34813 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-5194-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-34813 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2021-34813 · Vendor Advisory
• https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-04871 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-34813 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-34813 · Security Note
• https://osv.dev/vulnerability/USN-5194-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-34813 · Vendor Advisory