CVE-2021-21424 - CVE House
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Status published Medium CVE-2021-21424

Prevent user enumeration using Guard or the new Authenticator-based Security

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

symfony
Vulnerable Versions:
>= 2.8.0, < 3.4.48, >= 4.0.0, < 4.4.23, >= 5.0.0, < 5.2.8

Timeline

Official Publish: May 13th, 2021
Last Modified: August 3rd, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Weaknesses (CWE)