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.

How to fix CVE-2021-21424

To remediate CVE-2021-21424, upgrade the affected package to a fixed version below.

• —upgrade to 3.4.48 or later
• —upgrade to 4.4.19+dfsg-2 or later
• —upgrade to 3.4.22+dfsg-2+deb10u2 or later
• —upgrade to 2.10.7 or later
• —upgrade to 1.29.2 or later
• —upgrade to 5.2.8 or later
• —upgrade to 3.4.48 or later
• —upgrade to 3.4.48 or later
• —upgrade to 5.2.8 or later
• —upgrade to 3.4.49 or later

Is CVE-2021-21424 being exploited?

Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.

Affected packages (10)

• >= 2.8.0, < 3.4.48, >= 4.0.0, < 4.4.23, >= 5.0.0, < 5.2.8
• from 0, < 4.4.19+dfsg-2
• from 0, < 3.4.22+dfsg-2+deb10u2
• >= 2.0.0, < 2.10.7
• >= 1.27.0, < 1.29.2
• >= 5.0.0, < 5.2.8
• >= 2.8.0, < 3.4.48
• >= 2.8.0, < 3.4.48
• >= 5.1.0, < 5.2.8
• >= 2.8.0, < 3.4.49

CVSS scores

References (25)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-21424
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-21424
• PATCHgithub.com/symfony/symfony
• WEBgithub.com/FriendsOfPHP/security-advisories/blob/master/lexik/jwt-authentication-bundle/CVE-2021-21424.yaml