Joomla! com_users Debug Views Cross-Site Scripting Vulnerability [CVE-2019-11809]

CVE Number – CVE-2019-11809

A vulnerability in Joomla! could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack on a targeted system.

The vulnerability exists because the debug views of the com_users component of the affected software do not properly escape user-supplied data. An attacker could exploit this vulnerability by persuading a targeted user to follow a link that submits malicious input to the targeted system. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive browser-based information. 

Joomla! has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker may use misleading language or instructions to persuade a user to access a link that submits malicious input to the targeted system.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Administrators are advised to use an unprivileged account when browsing the Internet.
  
  Administrators are advised to monitor critical systems.
  
  Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
  
  Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.

Vendor Announcements

• Joomla! has released a security announcement at the following link: [20190501] – Core – XSS in com_users ACL debug views

Fixed Software

• Joomla! has released software updates at the following link: Joomla! 3.9.6