Auth bypass in Mailu

CVE-2020-5239

In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and gain full access to a Mailu instance. Mailu servers that have open registration or untrusted users are most impacted. The master and 1.7 branches are patched on our git repository. All Docker images published on docker.io/mailu for tags 1.5, 1.6, 1.7 and master are patched. For detailed instructions about patching and securing the server afterwards, see https://github.com/Mailu/Mailu/issues/1354

Vulnerability class: Broken Access Control

EPSS: 0.009 (55.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-5239?
CVE-2020-5239 is a high-severity vulnerability in Mailu, classified under Incorrect Authorization. CVSS score: 8.7/10. Published 2020-02-13.
How severe is CVE-2020-5239?
High severity. CVSS v3 base score is 8.7 out of 10.
Is CVE-2020-5239 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.