CVE-2021-33913

Name	CVE-2021-33913
Description	libspf2 before 1.2.11 has a heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of SPF_record_expand_data in spf_expand.c. The amount of overflowed data depends on the relationship between the length of an entire domain name and the length of its leftmost label. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.
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-2890-1, ELA-544-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libspf2 (PTS)	jessie, jessie (lts)	1.2.10-5+deb8u2	fixed
	stretch (security), stretch (lts), stretch	1.2.10-7+deb9u2	fixed
	buster (security), buster, buster (lts)	1.2.10-7.1~deb10u1	fixed
	bullseye (security), bullseye	1.2.10-7.1~deb11u1	fixed
	bookworm	1.2.10-7.2	fixed
	sid, trixie	1.2.10-8.2	fixed

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

Package	Type	Release	Fixed Version	Origin
libspf2	source	jessie	1.2.10-5+deb8u2	ELA-544-1
libspf2	source	stretch	1.2.10-7+deb9u2	DLA-2890-1
libspf2	source	buster	1.2.10-7.1~deb10u1
libspf2	source	bullseye	1.2.10-7.1~deb11u1
libspf2	source	(unstable)	1.2.10-7.1

Notes

https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosure
https://github.com/shevek/libspf2/pull/35
https://github.com/shevek/libspf2/commit/f06fef6cede4c4cb42f2c617496e6041782d7070