Is CVE-2021-34813 actively exploited?

CVE-2021-34813 has no public evidence of in-the-wild exploitation as of 2024-11-21.

What is the CVSS score for CVE-2021-34813?

CVE-2021-34813 has a CVSS score of 9.8 (CRITICAL severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2021-34813?

Patch guidance is available from matrix security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-34813.

Fix CVE-2021-34813 - CRITICAL matrix olm

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 Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-787 · Out-of-bounds Write

Metadata

Primary Vendor: MATRIX
Published: 6/16/2021
Last Modified: 11/21/2024
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

matrix : olm

Remediation Guidance

Executive Summary

Cite this page

CVE-2021-34813. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2021-34813

View on NIST NVD

CVE-2021-34813 vulnerability