CVE-2020-28024

Name	CVE-2020-28024
Description	Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary commands, because smtp_ungetc was only intended to push back characters, but can actually push back non-character error codes such as EOF.
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-2650-1, DSA-4912-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
exim4 (PTS)	bullseye	4.94.2-7+deb11u3	fixed
	bullseye (security)	4.94.2-7+deb11u4	fixed
	bookworm	4.96-15+deb12u6	fixed
	bookworm (security)	4.96-15+deb12u5	fixed
	sid, trixie	4.98-2	fixed

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

Package	Type	Release	Fixed Version	Origin
exim4	source	stretch	4.89-2+deb9u8	DLA-2650-1
exim4	source	buster	4.92-8+deb10u6	DSA-4912-1
exim4	source	(unstable)	4.94.2-1

https://www.openwall.com/lists/oss-security/2021/05/04/7