CVEvulnerability

CVE-2021-44538

9.8 CRITICAL Published 2021-12-14 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-12-14
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected])
7.5 HIGH — AV:N/AC:L/Au:N/C:P/I:P/A:P
Weaknesses
CWE-119

Description

The olm_session_describe function in Matrix libolm before 3.2.7 is vulnerable to a buffer overflow. The Olm session object represents a cryptographic channel between two parties. Therefore, its state is partially controllable by the remote party of the channel. Attackers can construct a crafted sequence of messages to manipulate the state of the receiver's session in such a way that, for some buffer sizes, a buffer overflow happens on a call to olm_session_describe. Furthermore, safe buffer sizes were undocumented. The overflow content is partially controllable by the attacker and limited to ASCII spaces and digits. The known affected products are Element Web And SchildiChat Web.

Affected configurations

• matrix element (< 1.9.7) • matrix javascript sdk (>= 2.4.2 < 15.2.1) • matrix olm (>= 3.1.4 < 3.2.8) • schildi schildichat (< 1.9.7-sc1) • cinny project cinny (< 1.6.0) • debian debian linux 9.0 • debian debian linux 10.0 • debian debian linux 11.0

Related

Weakness · CWE (1)

  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer weakness

References