Affected versions
Symfony 5.3.14, 5.4.3, and 6.0.3 versions of the Symfony Framework Bundle is affected by this security issue.
The issue has been fixed in Symfony 5.3.15, 5.4.4, and 6.0.4.
Description
The Symfony form component provides a CSRF protection mechanism by using a random token injected in the form and using the session to store and control the token submitted by the user. When using the FrameworkBundle, this protection can be enabled or disabled with the configuration. If the configuration is not specified, by default, the mechanism is enabled as long as the session is enabled.
In a recent change in the way the configuration is loaded, the default behavior has been dropped and, as a result, the CSRF protection is not enabled in form when not explicitly enabled, which makes the application sensible to CSRF attacks.
Resolution
Symfony restored the default configuration to enable the CSRF protection by default.
The patch for this issue is available here for branch 5.3.
Credits
We would like to thank Catalin Dan and David Lochner for reporting the issue and Jérémy Derussé for fixing the issue.
You can check if CSRF protection is enabled with command:
php bin/console debug:config framework csrf_protection.enabled
does this affect 4.4.x branch? It seems, based on the post above, that it does not, yet GitHub is generating dependabot warnings about it on 4.4.x projects. Additionally, the suggested CSRF checker command in the comment above shows a value of NULL on all 4.4 projects of mine.
To clarify on my above comment, despite seeing a NULL value for
php bin/console debug:config framework csrf_protection.enabled
my forms do have hidden *_token values and do appear to properly handle csrf. Am I missing something, or does the null value indicate that these systems are using the default value of true?
Hello, it seems just versions released on January 28 are affected - https://twitter.com/fabpot/status/1487743275318628358. So 4.4 should be safe.
@Philip Ardery False alerts could have been reported because of wrong version ranges: https://github.com/Roave/SecurityAdvisories/issues/90#issuecomment-1026617126