CVE-2022-39254

moderate-risk
Published 2022-09-29

matrix-nio is a Python Matrix client library, designed according to sans I/O principles. Prior to version 0.20, when a users requests a room key from their devices, the software correctly remember the request. Once they receive a forwarded room key, they accept it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.20 fixes the issue.

Do I need to act?

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0.24% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.6/10 High
NETWORK / LOW complexity

Affected Products (1)

Matrix-Nio

Affected Vendors

35
/ 100
moderate-risk
Severity 29/34 · Critical
Exploitability 1/34 · Minimal
Exposure 5/34 · Minimal