CVE-2019-20527

Vulnerability

Details

CVE-2019-20527 describes a reflected cross-site scripting (XSS) vulnerability in Ignite Realtime Openfire version 4.4.1. The flaw exists in the setup/setup-datasource-standard.jsp page, where the serverURL parameter is not properly sanitized before being reflected back to the user. An attacker can inject arbitrary JavaScript code via this parameter, which will execute in the context of the victim's browser session [1][2].

Attack

Vector

To exploit this vulnerability, an attacker must trick a user into visiting a crafted URL or submitting a malicious POST request to the vulnerable setup page. The attack does not require authentication, as the setup wizard is typically accessible without credentials, but it does require user interaction (e.g., clicking a link) [2]. The advisory from Netsparker (now Invicti) confirms that the serverURL parameter is one of several reflected XSS vectors in this page, with the attack pattern using an onmouseover event to trigger the payload [2]. The CVSSv3 score is 6.1 (Medium), reflecting a network-exploitable vulnerability with low complexity and no privileges required [2].

Impact

Successful exploitation allows an attacker to execute arbitrary HTML and JavaScript in the victim's browser. This can lead to session hijacking, defacement, or theft of sensitive information displayed on the page. Since the setup wizard is part of the initial configuration process, a compromised instance could be used to trick administrators into performing unintended actions during setup [1][2].

Mitigation

The vendor, Ignite Realtime, released a fix on September 25, 2019, which was included in a subsequent update. Users running Openfire 4.4.1 or earlier versions should upgrade to a patched release as soon as possible [2]. No workarounds are documented; upgrading is the recommended mitigation.