No exploitation reportedFix available

CVE-2021-38562

Q: Is CVE-2021-38562 actively exploited?

Active exploitation of CVE-2021-38562 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-38562?

CVE-2021-38562 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

No exploitation reported by the sources we read.

Published2021-10-18
Fixed in5.0.2 · 4.4.5 · 4.2.17
WeaknessCWE-203

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Best Practical Request Tracker (RT) 4.2 before 4.2.17, 4.4 before 4.4.5, and 5.0 before 5.0.2 allows sensitive information disclosure via a timing attack against lib/RT/REST2/Middleware/Auth.pm.

Timeline

dates in UTC

2021-10-1809:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-38562?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-38562?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Bestpractical request tracker

Branch	Affected	Fixed in	Source
5.0	≥ 5.0.0, < 5.0.2	5.0.2	NVD
4.4	≥ 4.4.0, < 4.4.5	4.4.5	NVD
4.2	≥ 4.2.0, < 4.2.17	4.2.17	NVD

Debian debian linux

Branch	Affected	Fixed in	Source
9.0	= 9.0	no fix published	NVD

Fedoraproject fedora

Branch	Affected	Fixed in	Source
35.x	= 35	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Bestpractical request tracker to 5.0.2 · 4.4.5 · 4.2.17

Advisories and patches

docs.bestpractical.comVendor Advisory
github.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
NVDweakness (CWE)CWE-203read 2026-10-23
FIRST EPSSEPSS score1.8 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published: 2021-10-18
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-38562?

Best Practical Request Tracker (RT) 4.2 before 4.2.17, 4.4 before 4.4.5, and 5.0 before 5.0.2 allows sensitive information disclosure via a timing attack against lib/RT/REST2/Middleware/Auth.pm.

Is CVE-2021-38562 actively exploited?

Active exploitation of CVE-2021-38562 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-38562?

CVE-2021-38562 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

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