GHSA-g2qj-pmxm-9f8f User enumeration in authentication mechanisms
Attackers can enumerate valid usernames via distinct error messages or timing differences in Symfony authentication, requiring a patch to standardize responses.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-g2qj-pmxm-9f8f?
GHSA-g2qj-pmxm-9f8f is a vulnerability in symfony/security-http, published on 17 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Description
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.
Resolution
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.
Credits
I would like to thank James Isaac and Mathias Brodala for reporting the issue and Robin Chalas for fixing the issue.
Which versions are affected by GHSA-g2qj-pmxm-9f8f?
4 open source packages ship an affected version, including symfony/security-http and symfony/symfony.
| Package | Affected | Fixed in |
|---|---|---|
symfony/security-http Packagist | From 5.1.0 | 5.2.8 |
symfony/security-http Packagist | From 5.1.0 | 5.2.8 |
symfony/symfony Packagist | From 5.1.0 | 5.2.8 |
symfony/symfony Packagist | From 5.1.0 | 5.2.8 |
How do I fix GHSA-g2qj-pmxm-9f8f?
Upgrade symfony/security-http to 5.2.8 or later.
Is GHSA-g2qj-pmxm-9f8f being exploited?
There is no known exploitation of GHSA-g2qj-pmxm-9f8f in the wild and no public exploit code.