What is CVE-2021-28377?

CVE-2021-28377 is a medium-severity vulnerability in Chronoengine Chronoforums, classified under Path Traversal. CVSS score: 5.3/10. Published 2022-01-12.

How severe is CVE-2021-28377?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Is CVE-2021-28377 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Path Traversal in Chronoengine Chronoforums

CVE-2021-28377

ChronoForums 2.0.11 allows av Directory Traversal to read arbitrary files.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2022-01-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.084 (94.8th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 94.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.084 · newest: 0.084 · change: 0.000

Affected products

Chronoengine Chronoforums — versions 2.0.11

Weakness classification (CWE)

CWE-22 — Path Traversal

Public proof-of-concept exploits

References

herolab.usd.de/en/security-advisories/usd-2021-0007/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-28377?: CVE-2021-28377 is a medium-severity vulnerability in Chronoengine Chronoforums, classified under Path Traversal. CVSS score: 5.3/10. Published 2022-01-12.
How severe is CVE-2021-28377?: Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-28377 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.