CVE-2024-50343: Incorrect response from Validator when input ends with `\n`

November 6, 2024 • Published by Fabien Potencier

Affected versions

Symfony versions <5.4.43; >=6, <6.4.11; >=7, <7.1.4 of the Symfony Validator component are affected by this security issue.

The issue has been fixed in Symfony 5.4.43, 6.4.11, and 7.1.4.

Description

It is possible to trick a Validator configured with a regular expression using the $ metacharacters, with an input ending with \n.

Resolution

Symfony now uses the D regex modifier to match the entire input.

The patch for this issue is available here for branch 5.4.

Credits

We would like to thank Offscript for reporting the issue and Alexandre Daubois for providing the fix.

Published in #Security Advisories

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Comments

Nicolas Grekas said on Nov 6, 2024 at 14:54

Here is the list of affected constraints: CardSchemeValidator, CssColorValidator, DateValidator, EmailValidator, TimeValidator and UrlValidator

Note also that if you're using the form component, it trims values by default so that you're not affected for the user input that goes through it.