IPFire < v2.29 Stored XSS via Remote Syslog Server Address

IPFire versions prior to 2.29 (Core Update 198) contain a stored cross-site scripting (XSS) vulnerability that allows an authenticated attacker to inject arbitrary JavaScript code through the REMOTELOG_ADDR parameter when updating the remote syslog server address. When a user updates the Remote logging Syslog server, the application issues an HTTP POST request to /cgi-bin/logs.cgi/config.dat and the server address is provided in the REMOTELOG_ADDR parameter. The value of this parameter is stored and later rendered in the web interface without proper sanitation or encoding, allowing injected scripts to execute in the context of other users who view the affected configuration page.