The ability to enumerate users was possible without relevant permissions due to different exception messages depending on whether the user existed or not. It was also possible to enumerate users by using a timing attack, by comparing time elapsed when authenticating an existing user and authenticating a non-existing user.
We now ensure that 403s are returned whether the user exists or not if the password is invalid or if the user does not exist.
The patch for this issue is available here for branch 3.4.
I would like to thank James Isaac and Mathias Brodala for reporting the issue and Robin Chalas for fixing the issue.
github.com/FriendsOfPHP/security-advisories/blob/master/lexik/jwt-authentication-bundle/CVE-2021-21424.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/symfony/maker-bundle/CVE-2021-21424.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-guard/CVE-2021-21424.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2021-21424.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security/CVE-2021-21424.yaml
github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2021-21424.yaml
github.com/symfony/symfony
github.com/symfony/symfony/commit/2a581d22cc621b33d5464ed65c4bc2057f72f011
github.com/symfony/symfony/security/advisories/GHSA-5pv8-ppvj-4h68
lists.debian.org/debian-lts-announce/2023/07/msg00014.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KENRNLB3FYXYGDWRBH2PDBOZZKOD7VY4
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RH7TMM5CHQYBFFGXWRPJDPB3SKCZXI2M
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UC7BND775DVZDQT3RMGD2HVB2PKLJDJW
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VRUS2H2SSOQWNLBD35SKIWIDQEMV2PD3
lists.fedoraproject.org/archives/list/[email protected]/message/KENRNLB3FYXYGDWRBH2PDBOZZKOD7VY4
lists.fedoraproject.org/archives/list/[email protected]/message/RH7TMM5CHQYBFFGXWRPJDPB3SKCZXI2M
lists.fedoraproject.org/archives/list/[email protected]/message/UC7BND775DVZDQT3RMGD2HVB2PKLJDJW
lists.fedoraproject.org/archives/list/[email protected]/message/VRUS2H2SSOQWNLBD35SKIWIDQEMV2PD3
nvd.nist.gov/vuln/detail/CVE-2021-21424
symfony.com/cve-2021-21424