Auth bypass in Canonical Python-Apt

CVE-2019-15796

Python-apt doesn't check if hashes are signed in `Version.fetch_binary()` and `Version.fetch_source()` of apt/package.py or in `_fetch_archives()` of apt/cache.py in version 1.9.3ubuntu2 and earlier. This allows downloads from unsigned repositories which shouldn't be allowed and has been fixed in verisions 1.9.5, 1.9.0ubuntu1.2, 1.6.5ubuntu0.1, 1.1.0~beta1ubuntu0.16.04.7, 0.9.3.5ubuntu3+esm2, and 0.8.3ubuntu7.5.

Vulnerability class: Broken Authentication

EPSS: 0.005 (42.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-15796?
CVE-2019-15796 is a medium-severity vulnerability in Canonical Python-Apt, classified under Improper Authentication. CVSS score: 4.7/10. Published 2020-03-26.
How severe is CVE-2019-15796?
Medium severity. CVSS v3 base score is 4.7 out of 10.