How severe is CVE-2017-18343?

CVE-2017-18343 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2017-18343 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-18343?

CVE-2017-18343 affects Sensiolabs Symfony. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-18343?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-18343 published?

CVE-2017-18343 was published on 2018-07-20 and last updated on 2026-06-17.

CVE-2017-18343

CVE-2017-18343 is a medium-severity vulnerability in Sensiolabs Symfony with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 6% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Sensiolabs Symfony
Published: 2018-07-20
Last modified: 2026-06-17

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

Frequently asked questions

What is CVE-2017-18343?: 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
How severe is CVE-2017-18343?: CVE-2017-18343 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2017-18343 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-18343?: CVE-2017-18343 affects Sensiolabs Symfony. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-18343?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-18343 published?: CVE-2017-18343 was published on 2018-07-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*

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