CVE-2021-31866

critical

Published — · Modified —

CVSS v3

—

CVSS v2

—

VIR risk

9.5

Description

Redmine before 4.0.9 and 4.1.x before 4.1.3 allows an attacker to learn the values of internal authentication keys by observing timing differences in string comparison operations within SysController and MailHandlerController.

Predictions

Exploit likelihood

20%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-31866

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202105-1

OS impact

OS	Version	Status	Fixed in
arch		fixed	`4.2.1-1`
debian	bookworm	fixed	`5.0.0-1`
debian	sid	fixed	`5.0.0-1`
debian	trixie	fixed	`5.0.0-1`

References

https://security.archlinux.org/ASA-202105-1
https://security-tracker.debian.org/tracker/CVE-2021-31866

Verify integrity in audit chain (admin only). AS-IS.