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CVE-2021-21404

CVE information

Published

3 years ago

Last Modified

3 years ago

CVSSv2.0 Severity

Medium

CVSSv3.1 Severity

High

Impact Analysis

Description

Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it's likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0..

CVSSv2.0 Score

Severity
Medium
Base Score
5/10
Exploit Score
10/10
Access Vector
Network
Access Complexity
Low
Authentication Required
None
Impact Score
2.9/10
Confidentiality Impact
None
Availability Impact
Partial
Integrity Impact
None

CVSSv3.1 Score

Severity
High
Base Score
7.5/10
Exploit Score
3.9/10
Access Vector
Network
Access Complexity
Low
Privileges Required
None
Impact Score
3.6/10
Confidentiality Impact
None
Availability Impact
High
Integrity Impact
None
Scope
Unchanged
User Interaction
None

Products Affected

CPE Affected Vulnerable Excluding Edit
cpe:2.3:a:syncthing:syncthing:*:*:*:*:*:*:*:*
  Yes
- 1.15.0