CVE-2021-30164 [Critical] | Security Bypass in Redmine

CVE-2021-30164 is rated Moderate Risk (63.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.32%). EPSS rose +1.11% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.21%

1.32%

+1.11%

2025-11-21

0.39%

0.21%

-0.18%

2025-11-18

—

0.39%

—

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

OS Trackers for CVE-2021-30164

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-30164 not yet assigned priority: Debian including 1 source packages (redmine), 3 status rows across 3 suites (bookworm, sid, trixie): resolved 3.	https://security-tracker.debian.org/tracker/CVE-2021-30164
`ubuntu`	medium	CVE-2021-30164 medium priority: Ubuntu including 1 source packages (redmine), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 8, ignored 4, needs-triage 4.	https://ubuntu.com/security/CVE-2021-30164

Affected software / configurations for CVE-2021-30164

Vendor	Product	Version	Raw CPE
redmine	redmine	< 4.0.8	cpe:2.3:a:redmine:redmine::::::::
redmine	redmine	>= 4.1.0, < 4.1.2	cpe:2.3:a:redmine:redmine::::::::
debian	debian_linux	9.0	cpe:2.3:o:debian:debian_linux:9.0:::::::*

References for CVE-2021-30164

URL

URL	Tags
https://lists.debian.org/debian-lts-announce/2021/05/msg00013.html	Mailing List Third Party Advisory
https://www.redmine.org/projects/redmine/wiki/Security_Advisories	Not Applicable

CVE-2021-30164

Exploit prediction scoring system (EPSS) score for CVE-2021-30164

Common vulnerability scoring system (CVSS) metrics for CVE-2021-30164

Weakness enumeration for CVE-2021-30164

OS Trackers for CVE-2021-30164

Affected software / configurations for CVE-2021-30164

References for CVE-2021-30164

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]