CVE-2021-32066

Name	CVE-2021-32066
Description	An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a "StartTLS stripping attack."
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-2780-1, DLA-3408-1, DSA-5066-1
Debian Bugs	990815, 1014818

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
jruby (PTS)	bookworm	9.3.9.0+ds-8	fixed
	forky, trixie	9.4.8.0+ds-3	fixed
	sid	9.4.14.0+ds-1	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
jruby	source	buster	9.1.17.0-3+deb10u1	DLA-3408-1
jruby	source	(unstable)	9.3.9.0+ds-1		1014818
ruby2.3	source	stretch	2.3.3-1+deb9u10	DLA-2780-1
ruby2.3	source	(unstable)	(unfixed)
ruby2.5	source	buster	2.5.5-3+deb10u4	DSA-5066-1
ruby2.5	source	(unstable)	(unfixed)
ruby2.7	source	(unstable)	2.7.4-1		990815

Notes

[stretch] - jruby <no-dsa> (Minor issue)
https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/
https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a (2.7)