CVE Vulnerability

CVE-2021-21404

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.

5 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 2.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

Scope

7.5 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/syncthing/syncthing/releases/tag/v1.15.0 Release Notes Third Party Advisory
https://github.com/syncthing/syncthing/commit/fb4fdaf4c0a79c22cad000c42ac1394e3ccb6a97 Patch Third Party Advisory
https://github.com/syncthing/syncthing/security/advisories/GHSA-x462-89pf-6r5h Third Party Advisory
https://pkg.go.dev/github.com/syncthing/syncthing Product Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:syncthing:syncthing:*:*:*:*:*:*:*:*
Information

Published : 2021-04-06 08:15

Updated : 2021-04-14 06:00

NVD link : CVE-2021-21404

Mitre link : CVE-2021-21404

Products Affected
No products.
CWE
CWE-20