WordPress Broken Link Checker Plugin CVE-2019-17207 Cross Site Scripting Vulnerability

Description

Broken Link Checker plugin for WordPress is prone to a cross-site scripting vulnerability because it fails to properly sanitize user-supplied input. An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This can allow the attacker to steal cookie-based authentication credentials and launch other attacks. Broken Link Checker version 1.11.8 is vulnerable;other versions may also be affected.

Technologies Affected

• WordPress Broken Link Checker 1.11.8

Recommendations

Configure webservers to serve only specific, defined file types.
Web users should be cautious about following links to websites that are provided by unfamiliar or suspicious sources. Filtering HTML from emails may help remove a possible vector for transmitting malicious links to users.

Block external access at the network boundary, unless external parties require service.
Filter access to the affected computer at the network boundary if global access isn’t needed. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.

Run all software as a nonprivileged user with minimal access rights.
Ensure that all nonadministrative tasks, such as browsing the web and reading email, are performed as an unprivileged user with minimal access rights.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review logs regularly.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This may indicate exploit attempts or activity that results from a successful exploit.

Set web browser security to disable the execution of JavaScript.
Since exploiting cross-site scripting issues often requires malicious script code to run in browsers, consider disabling script code and active content support within a client browser as a way to prevent a successful exploit. Note that this mitigation tactic might adversely affect legitimate sites that rely on the execution of browser-based script code.

Currently, we are not aware of any vendor-supplied patches. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].