Vulnerability 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 Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| 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 |
Related Weaknesses (CWE)
References
- https://gitlab.matrix.org/matrix-org/olm/-/tagsProductThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListThird Party Advisory
- https://matrix.org/blog/2021/12/13/disclosure-buffer-overflow-in-libolm-and-matrPatchVendor Advisory
- https://www.debian.org/security/2022/dsa-5034Third Party Advisory
- https://gitlab.matrix.org/matrix-org/olm/-/tagsProductThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing ListThird Party Advisory
- https://matrix.org/blog/2021/12/13/disclosure-buffer-overflow-in-libolm-and-matrPatchVendor Advisory
- https://www.debian.org/security/2022/dsa-5034Third Party Advisory
FAQ
What is CVE-2021-44538?
CVE-2021-44538 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 ...
How severe is CVE-2021-44538?
CVE-2021-44538 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-44538?
Check the references section above for vendor advisories and patch information. Affected products include: Matrix Element, Matrix Javascript Sdk, Matrix Olm, Schildi Schildichat, Cinny Project Cinny.