CVE-2017-11424

Name	CVE-2017-11424
Description	In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-3979-1
Debian Bugs	873244

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pyjwt (PTS)	jessie, jessie (lts)	0.2.1-1+deb8u2	fixed
	stretch (security), stretch (lts), stretch	1.4.2-1+deb9u1	fixed
	buster	1.7.0-2	fixed
	bullseye	1.7.1-2	fixed
	bookworm	2.6.0-1	fixed
	sid, trixie	2.7.0-1	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
pyjwt	source	jessie	0.2.1-1+deb8u2	DSA-3979-1
pyjwt	source	stretch	1.4.2-1+deb9u1	DSA-3979-1
pyjwt	source	(unstable)	1.4.2-1.1		873244

https://github.com/jpadilla/pyjwt/pull/277