CVE-2021-31866
Redmine before 4.0.9 and 4.1.x before 4.1.3 allows an attacker to learn the values of internal...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-31866- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-31866- Updated
- 2026-11-02
EUVDEUVD-2021-18741 No score
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.
- Record
EUVD-2021-18741- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gv7v-mp3w-gfvh
Redmine before 4.0.9 and 4.1.x before 4.1.3 allows an attacker to learn the values of internal...
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.
- Record
GHSA-gv7v-mp3w-gfvh- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-31866- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-31866
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.
- Record
DEBIAN-CVE-2021-31866- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-31866
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.
- Record
UBUNTU-CVE-2021-31866- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVBIT-redmine-2021-31866 No score
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.
- Record
BIT-redmine-2021-31866- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
redmineBitnami |
before 4.0.9, 4.1.0 up to 4.1.3 | 4.0.94.1.3 |
redmineDebian:12 |
before 5.0.0-1 | 5.0.0-1 |
redmineDebian:13 |
before 5.0.0-1 | 5.0.0-1 |
redmineDebian:14 |
before 5.0.0-1 | 5.0.0-1 |
redmineDebian:9 From an advisory covering 10 CVEs |
before 3.3.1-4+deb9u4, plus listed versions 3.3.1-43.3.1-4+deb9u13.3.1-4+deb9u23.3.1-4+deb9u3 |
3.3.1-4+deb9u4 |
redmineUbuntu:16.04:LTS |
All versions, plus listed versions 3.0~20140825-83.2.0-13.2.0-33.2.1-13.2.1-23.2.1-2ubuntu0.2 |
None known |
redmineUbuntu:18.04:LTS |
All versions, plus listed versions 3.3.1-43.4.2-13.4.4-13.4.4-1ubuntu0.1 |
None known |
redmineUbuntu:20.04:LTS |
All versions, plus listed versions 4.0.4-14.0.4-34.0.6-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-31866 is a medium vulnerability (CVSS 5.3) in Redmine, published April 28, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.23%, the 68th percentile. Fixed in redmine 4.0.9.
References
redmine.org/projects/redmine/wiki/Security_Advisories
lists.debian.org/debian-lts-announce/2021/05/msg00013.html
nvd.nist.gov/vuln/detail/CVE-2021-31866
github.com/advisories/GHSA-gv7v-mp3w-gfvh
security-tracker.debian.org/tracker/CVE-2021-31866
ubuntu.com/security/CVE-2021-31866
cve.org/CVERecord?id=CVE-2021-31866