CVE-2019-18886:
User enumeration leak using switch user functionality in Symfony
5.3
CVSS Score
3.1
Basic Information
CVE ID
GHSA ID
EPSS Score
0.8056%
CWE
Published
12/2/2019
Updated
2/1/2023
KEV Status
No
Technology
PHP
PHPTechnical Details
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
| Package Name | Ecosystem | Vulnerable Versions | First Patched Version |
|---|---|---|---|
| symfony/security-http | composer | >= 4.1.0, < 4.2.12 | 4.2.12 |
| symfony/security-http | composer | >= 4.3.0, < 4.3.8 | 4.3.8 |
| symfony/symfony | composer | >= 4.1.0, < 4.2.12 | 4.2.12 |
| symfony/symfony | composer | >= 4.3.0, < 4.3.8 | 4.3.8 |
Vulnerability Intelligence
Miggo AI
Miggo AIRoot Cause Analysis
The vulnerability stems from inconsistent error handling in the user switching process. Before patching, the SwitchUserListener would first check for user existence before checking switching permissions. If the user didn't exist, it would throw a UsernameNotFoundException (potentially resulting in 404), while existing but unauthorized attempts threw AccessDeniedException (403). The fix in 4.2.12/4.3.8 standardized this to always throw AccessDeniedException regardless of user existence, as confirmed by Symfony's security advisory and commit messages referencing the SwitchUserListener changes.