Detections
Analytics

Symfony Conflicting Headers Information Disclosure

medium Web App Scanning Plugin ID 115099

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Synopsis

Symfony Conflicting Headers Information Disclosure

Description

The remote web application is using Symfony, a PHP framework. It is affected by an information disclosure vulnerability arising from conflicting proxy headers.

When both 'Forwarded' and 'X-Forwarded-*' headers are present in a request, a misconfiguration in Symfony's trusted proxy settings can trigger a 'ConflictingHeadersException'. If the application is running with debug mode enabled in a production environment, this exception can expose sensitive environment details, such as SMTP credentials, internal application paths, and system configuration.

Solution

Disable debug mode in production environments. Review and update the application's 'trusted_proxies' configuration to ensure it correctly handles incoming headers. Configure the application to prioritize or strictly define which proxy headers (standard 'Forwarded' vs 'X-Forwarded-*') are accepted, preventing conflicts.

See Also

https://symfony.com/doc/current/deployment/proxies.html

Plugin Details

Severity: Medium

ID: 115099

Type: remote

Published: 1/7/2026

Updated: 1/7/2026

Scan Template: api, basic, full, pci, scan

Risk Information

VPR

Risk Factor: Low

Score: 2.9

CVSS v2

Risk Factor: Medium

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: Tenable

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS Score Source: Tenable

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS Score Source: Tenable

Reference Information