CVE-2024-9681

Name	CVE-2024-9681
Description	When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's cache entry, making it end sooner or later than otherwise intended. This affects curl using applications that enable HSTS and use URLs with the insecure `HTTP://` scheme and perform transfers with hosts like `x.example.com` as well as `example.com` where the first host is a subdomain of the second host. (The HSTS cache either needs to have been populated manually or there needs to have been previous HTTPS accesses done as the cache needs to have entries for the domains involved to trigger this problem.) When `x.example.com` responds with `Strict-Transport-Security:` headers, this bug can make the subdomain's expiry timeout bleed over and get set for the parent domain `example.com` in curl's HSTS cache. The result of a triggered bug is that HTTP accesses to `example.com` get converted to HTTPS for a different period of time than what was asked for by the origin server. If `example.com` for example stops supporting HTTPS at its expiry time, curl might then fail to access `http://example.com` until the (wrongly set) timeout expires. This bug can also expire the parent's entry earlier, thus making curl inadvertently switch back to insecure HTTP earlier than otherwise intended.
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	1086804

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
curl (PTS)	jessie, jessie (lts)	7.38.0-4+deb8u28	fixed
	stretch (security)	7.52.1-5+deb9u16	fixed
	stretch (lts), stretch	7.52.1-5+deb9u22	fixed
	buster, buster (lts)	7.64.0-4+deb10u10	fixed
	buster (security)	7.64.0-4+deb10u9	fixed
	bullseye	7.74.0-1.3+deb11u13	vulnerable
	bullseye (security)	7.74.0-1.3+deb11u14	vulnerable
	bookworm	7.88.1-10+deb12u8	vulnerable
	bookworm (security)	7.88.1-10+deb12u5	vulnerable
	sid, trixie	8.11.0-1	fixed

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

Package	Type	Release	Fixed Version	Debian Bugs
curl	source	jessie	(not affected)
curl	source	stretch	(not affected)
curl	source	buster	(not affected)
curl	source	(unstable)	8.11.0-1	1086804

Notes

[bookworm] - curl <no-dsa> (Minor issue)
[bullseye] - curl <ignored> (curl is not built with HSTS support)
https://curl.se/docs/CVE-2024-9681.html
Introduced by: https://github.com/curl/curl/commit/7385610d0c74c6a254fea5e4cd6e1d559d848c8c (curl-7_74_0)
Fixed by: https://github.com/curl/curl/commit/a94973805df96269bf3f3bf0a20ccb9887313316 (curl-8_11_0)
[buster] - curl <not-affected> (HSTS support was introduced later)
[stretch] - curl <not-affected> (HSTS support was introduced later)
[jessie] - curl <not-affected> (HSTS support was introduced later)