Symfony 2.8.0 to 2.8.49, 3.4.0 to 3.4.25, 4.1.0 to 4.1.11 and 4.2.0 to 4.2.6 versions of the Symfony Cache component are affected by this security issue.
The issue has been fixed in Symfony 2.8.50, 3.4.26, 4.1.12 and 4.2.7.
Note that no fixes are provided for Symfony 3.0, 3.1, 3.2, 3.3, and 4.0 as they are not maintained anymore and that 2.7 is unaffected.
Description
When unserialize() is called with content coming from user input, malicious payloads could be used to trigger file deletions or raw output being echoed.
Resolution
We now prevent some classes from being serialized or unserialized.
The patch for this issue is available here for branch 3.4.
Credits
I would like to thank Mindaugas Vedegys for reporting the issue and Nicolas Grekas for fixing the issue.
Have found a security issue in Symfony? Send the details to
security [at] symfony.com and don't
disclose it publicly until we can provide a fix for it.
As with any Open-Source project, contributing
code or documentation is the most common way to help, but we also have a wide range of
sponsoring opportunities.