CVE-2021-21404 Detail

Current 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.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  GitHub, Inc.
Base Score:  7.5 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: The NVD and the CNA have provided the same score. When this occurs only the CNA information is displayed, but the Acceptance Level icon for the CNA is given a checkmark to signify NVD concurrence.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/syncthing/syncthing/commit/fb4fdaf4c0a79c22cad000c42ac1394e3ccb6a97 Patch  Third Party Advisory 
https://github.com/syncthing/syncthing/releases/tag/v1.15.0 Release Notes  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 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-20 Improper Input Validation Provider acceptance level GitHub, Inc.  

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Change History

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Quick Info

CVE Dictionary Entry:
CVE-2021-21404
NVD Published Date:
04/06/2021
NVD Last Modified:
04/14/2021
Source:
GitHub, Inc.