| Name | CVE-2021-21424 |
| Description | Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4. |
| 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-3493-1, ELA-912-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| symfony (PTS) | jessie, jessie (lts) | 2.3.21+dfsg-4+deb8u6 | vulnerable |
| stretch (security) | 2.8.7+dfsg-1.3+deb9u3 | vulnerable |
| stretch (lts), stretch | 2.8.7+dfsg-1.3+deb9u5 | fixed |
| buster (security), buster, buster (lts) | 3.4.22+dfsg-2+deb10u3 | fixed |
| bullseye | 4.4.19+dfsg-2+deb11u6 | fixed |
| bookworm | 5.4.23+dfsg-1+deb12u2 | fixed |
| bookworm (security) | 5.4.23+dfsg-1+deb12u4 | fixed |
| sid, trixie | 6.4.15+dfsg-1 | fixed |
The information below is based on the following data on fixed versions.
Notes
[stretch] - symfony <postponed> (Minor issue)
https://symfony.com/blog/cve-2021-21424-prevent-user-enumeration-in-authentication-mechanisms
https://github.com/symfony/symfony/commit/f012eee6c6034a94566dff596fe4e16dfc5d9c1f
[jessie] - symfony <postponed> (Fix along next ELA)