CVE-2021-3521

Name	CVE-2021-3521
Description	There is a flaw in RPM's signature functionality. OpenPGP subkeys are associated with a primary key via a "binding signature." RPM does not check the binding signature of subkeys prior to importing them. If an attacker is able to add or socially engineer another party to add a malicious subkey to a legitimate public key, RPM could wrongly trust a malicious signature. The greatest impact of this flaw is to data integrity. To exploit this flaw, an attacker must either compromise an RPM repository or convince an administrator to install an untrusted RPM or public key. It is strongly recommended to only use RPMs and public keys from trusted sources.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1014723

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
rpm (PTS)	bullseye	4.16.1.2+dfsg1-3	vulnerable
	bookworm	4.18.0+dfsg-1+deb12u1	fixed
	sid, trixie	4.20.0+dfsg-3	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rpm	source	(unstable)	4.18.0+dfsg-1			1014723

Notes

[bullseye] - rpm <no-dsa> (Minor issue)
[buster] - rpm <no-dsa> (Minor issue)
[stretch] - rpm <no-dsa> (Minor issue)
https://github.com/rpm-software-management/rpm/pull/1788
https://github.com/rpm-software-management/rpm/commit/bd36c5dc9fb6d90c46fbfed8c2d67516fc571ec8