9.8

CVE-2021-44538: cinny_project cinny

CVSS: 9.8v3.1CriticalModified
AliasesMGASA-2021-0571UBUNTU-CVE-2021-44538DEBIAN-CVE-2021-44538
Published 14-12-2021Last modified 04-08-2024

Vulnerability summary

CVE-2021-44538 is a critical (CVSS 9.8) vulnerability in cinny_project cinny. EPSS estimates a 1.98% chance of exploitation in the next 30 days, higher than 80.2% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
1.98%
0%100%
Low · +0.06 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 4

Timeline

  1. 14-12-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

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 metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

1.98%

Chance of exploitation in the next 30 days

Percentile

80%

Versus all other CVEs

30-day change

+0.06 pp

From 1.92% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.98%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian3 products
  • olm< 3.2.8~dfsg-1
  • thunderbird< 1:91.4.1-1
  • debian_linuxEOL9.0 | 10.0 | 11.0
Matrix3 products
Ubuntu3 products
  • node-matrix-js-sdkAll versions (No fix recorded)
  • olmAll versions (No fix recorded)
  • thunderbird< 1:91.5.0+build1-0ubuntu0.18.04.1 | < 1:91.5.0+build1-0ubuntu0.20.04.1 | < 1:91.5.0+build1-0ubuntu1
Cinny_project1 product
Mageia1 product
  • olm< 3.2.1-1.1.mga8
Schildi1 product

6 vendors · 12 products

References

13 links
Show all 13 references