CVE-2020-36478

Name	CVE-2020-36478
Description	An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-2826-1, DLA-3249-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mbedtls (PTS)	stretch (security), stretch (lts), stretch	2.4.2-1+deb9u4	fixed
	buster (security), buster, buster (lts)	2.16.9-0~deb10u1	fixed
	bullseye	2.16.9-0.1	fixed
	bookworm	2.28.3-1	fixed
	trixie	2.28.8-1	fixed
	sid	3.6.2-3	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin
mbedtls	source	stretch	2.4.2-1+deb9u4	DLA-2826-1
mbedtls	source	buster	2.16.9-0~deb10u1	DLA-3249-1
mbedtls	source	(unstable)	2.16.9-0.1

https://github.com/ARMmbed/mbedtls/issues/3629
https://github.com/ARMmbed/mbedtls/commit/ca17ebfbc02b57e2bcb42efe64a5f2002c756ea8 (development)