What is CVE-2021-28042?

CVE-2021-28042 is a high-severity vulnerability in Deutschepost Mailoptimizer, classified under Path Traversal. CVSS score: 7.8/10. Published 2021-03-05.

How severe is CVE-2021-28042?

High severity. CVSS v3 base score is 7.8 out of 10.

Path Traversal in Deutschepost Mailoptimizer

CVE-2021-28042

Deutsche Post Mailoptimizer 4.3 before 2020-11-09 allows Directory Traversal via a crafted ZIP archive to the Upload feature or the MO Connect component. This can lead to remote code execution.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2021-03-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.034 (88.6th percentile), scored 2026-10-09.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 88.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.033 · newest: 0.034 · change: +0.001

Affected products

Deutschepost Mailoptimizer — versions 4.3

Weakness classification (CWE)

CWE-22 — Path Traversal

References

herolab.usd.de/security-advisories/usd-2020-0028/ (Third Party Advisory)
www.deutschepost.de/de/m/mailoptimizer.html (Product)

Frequently asked questions

What is CVE-2021-28042?: CVE-2021-28042 is a high-severity vulnerability in Deutschepost Mailoptimizer, classified under Path Traversal. CVSS score: 7.8/10. Published 2021-03-05.
How severe is CVE-2021-28042?: High severity. CVSS v3 base score is 7.8 out of 10.