Executive Summary

CVE-2026-34799 is a stored cross-site scripting (XSS) vulnerability in Endian Firewall versions 3.3.25 and earlier. It occurs because the 'remark' parameter in the /manage/dnsmasq/hosts/ endpoint does not properly neutralize input, allowing an authenticated attacker to inject arbitrary JavaScript code.

This malicious code is stored on the server and executed whenever other users view the affected page, potentially compromising their interactions with the firewall management interface.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability allows an authenticated attacker to execute arbitrary JavaScript in the context of other users viewing the affected page, which can lead to session hijacking, unauthorized actions, or theft of sensitive information.

The impact is limited to users who access the vulnerable interface, and the attack requires authentication, but it can still compromise confidentiality and integrity of user sessions.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by checking for the presence of malicious JavaScript code injected via the "remark" parameter in the /manage/dnsmasq/hosts/ endpoint of Endian Firewall versions 3.3.25 and earlier.

Since the vulnerability requires authentication, detection involves reviewing the stored remarks for suspicious or unexpected JavaScript code.

Commands or methods to detect this might include:

• Using curl or similar tools to authenticate and retrieve the /manage/dnsmasq/hosts/ page content and inspecting the "remark" fields for embedded scripts.
• Example command: curl -k -u <username>:<password> https://<firewall-ip>/manage/dnsmasq/hosts/ | grep -i remark
• Using web vulnerability scanners that support authenticated scans to detect stored XSS in the remark parameter.

Useful 0 Not Useful 0

Mitigation Strategies

Immediate mitigation steps include:

• Upgrade Endian Firewall to a version later than 3.3.25 where this vulnerability is fixed.
• Restrict access to the /manage/dnsmasq/hosts/ endpoint to trusted and authenticated users only.
• Review and sanitize existing entries in the remark parameter to remove any injected JavaScript code.
• Implement web application firewall (WAF) rules to detect and block attempts to inject scripts via the remark parameter.

Useful 0 Not Useful 0

Compliance Impact

The provided information does not specify how CVE-2026-34799 affects compliance with common standards and regulations such as GDPR or HIPAA.

Useful 0 Not Useful 0