Redmine before 4.0.9, 4.1.x before 4.1.3, and 4.2.x before 4.2.1 allows users to circumvent the allowed filename extensions of uploaded att…

published 2021-04-28 5y ago modified 2026-09-08 2mo ago also BIT-redmine-2021-31865 , EUVD-2021-18740

cvss: 5.3; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits: 0; none known

Redmine before 4.0.9, 4.1.x before 4.1.3, and 4.2.x before 4.2.1 allows users to circumvent the allowed filename extensions of uploaded attachments.

Patch / fix

fixed in 2 distros 2

bitnami redmine 4.0.9, 4.1.3, 4.2.1
redmine redmine 4.0.9, 4.1.3, 4.2.1

debian arch linux

redmine Debian 14, Debian 13, Debian 12 5.0.0-1

debian advisories DEBIAN-CVE-2021-31865

redmine Arch Linux 4.2.1-1

arch linux advisories AVG-1743

Is CVE-2021-31865 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

1.13% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:P/A:N
OSV	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
bitnami	redmine	<4.0.9 >=4.1.0, <4.1.3 >=4.2.0, <4.2.1	4.0.9 4.1.3 4.2.1

References

redmine.org /projects/redmine/wiki/Security_Advisories
vendor-advisory, advisory
redmine.org /news/131
vendor-advisory, advisory
lists.debian.org /debian-lts-announce/2021/05/msg00013.html
mailing-list, third-party-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2021-31865
web

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary