CVE-2017-18343

Name: CVE-2017-18343
Creator: NVD / NIST
Published: 2018-07-20T00:29:00.237+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 6.11%

Last modified Jun 17, 2026

CVE-2017-18343 is a vulnerability of currently unknown severity. The debug handler in Symfony before v2.7.33, 2.8.x before v2.8.26, 3.x before v3.2.13, and 3.3.x before v3.3.6 has XSS via an array key during exception pretty printing in ExceptionHandler.php, as demonstrated by a /_debugbar/open?op=get URI. NOTE: the vendor's position is that this is not a vulnerability because the debug tools are not intended for production use. EPSS estimates a 6.11% chance of exploitation in the next 30 days.

Description

The debug handler in Symfony before v2.7.33, 2.8.x before v2.8.26, 3.x before v3.2.13, and 3.3.x before v3.3.6 has XSS via an array key during exception pretty printing in ExceptionHandler.php, as demonstrated by a /_debugbar/open?op=get URI. NOTE: the vendor's position is that this is not a vulnerability because the debug tools are not intended for production use. NOTE: the Symfony Debug component is used by Laravel Debugbar

Metrics

EPSS Probability

6.11%

92.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Sensiolabs	Symfony	< 2.7.33
Sensiolabs	Symfony	>= 2.8.0, < 2.8.26
Sensiolabs	Symfony	>= 3.0.0, < 3.2.13
Sensiolabs	Symfony	>= 3.3.0, < 3.3.6

References

https://github.com/barryvdh/laravel-debugbar/issues/850Exploit, Third Party Advisory
https://github.com/symfony/debug/pull/7/commits/e48bda29143bd1a83001780b4a78e483822d985cPatch, Third Party Advisory
https://github.com/symfony/symfony/issues/27987Exploit, Third Party Advisory
https://github.com/symfony/symfony/pull/23684Third Party Advisory
https://github.com/barryvdh/laravel-debugbar/issues/850Exploit, Third Party Advisory
https://github.com/symfony/debug/pull/7/commits/e48bda29143bd1a83001780b4a78e483822d985cPatch, Third Party Advisory
https://github.com/symfony/symfony/issues/27987Exploit, Third Party Advisory
https://github.com/symfony/symfony/pull/23684Third Party Advisory

Timeline

Published: Jul 20, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-18343?

How severe is CVE-2017-18343?

Severity scoring for CVE-2017-18343 is pending analysis. The EPSS model estimates a 6.11% probability of exploitation in the next 30 days.

How do I fix CVE-2017-18343?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2017-18343?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST