CVE-2021-44538
The olm_session_describe function in Matrix libolm before 3.2.7 is vulnerable to a buffer overflow.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.92%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- 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
- 1.92% probability · 79th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-119
- Affected
- matrix/element · matrix/javascript sdk · matrix/olm · schildi/schildichat · cinny project/cinny · debian/debian linux
- Source
- cve@mitre.org
References
- https://gitlab.matrix.org/matrix-org/olm/-/tagsProduct, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
- https://matrix.org/blog/2021/12/13/disclosure-buffer-overflow-in-libolm-and-matrix-js-sdkPatch, Vendor Advisory
- https://www.debian.org/security/2022/dsa-5034Third Party Advisory
- https://gitlab.matrix.org/matrix-org/olm/-/tagsProduct, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
- https://matrix.org/blog/2021/12/13/disclosure-buffer-overflow-in-libolm-and-matrix-js-sdkPatch, Vendor Advisory
- https://www.debian.org/security/2022/dsa-5034Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.