Vulnerability identifier: #VU59080

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-44538

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
olm
Universal components / Libraries / Libraries used by multiple products

Vendor: Matrix.org

Description

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to a boundary error within the olm_session_describe() function in libolm. A remote attacker send specially crafted messages to the application that is using the affected library, trigger buffer overflow and perform a denial of service (DoS) attack

Mitigation
Install updates from vendor's website.

Vulnerable software versions

olm: 3.0.0 - 3.2.7

---

External links
http://matrix.org/blog/2021/12/13/disclosure-buffer-overflow-in-libolm-and-matrix-js-sdk
http://gitlab.matrix.org/matrix-org/olm/-/tags

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.