Vulnerability · Published Jun 16, 2021 · Assigned by mitre
CVE-2021-34813
Critical 9.8
In plain English
A critical-severity security flaw in the olm package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 4.3% (higher than 91% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)9.8Critical
Exploit odds (30 days)4.3%top 8.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | olm | 3.2.3~dfsg-3 | DEBIAN-CVE-2021-34813 |
| Debian:13 | olm | 3.2.3~dfsg-3 | DEBIAN-CVE-2021-34813 |
| Debian:14 | olm | 3.2.3~dfsg-3 | DEBIAN-CVE-2021-34813 |