CVE-2024-25705 is a cross-site scripting (XSS) vulnerability identified in Esri Portal for ArcGIS Experience Builder version 11.1 and earlier, affecting both Windows and Linux deployments. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), allowing an attacker to inject malicious JavaScript code into web pages served by the portal. An unauthenticated remote attacker with low privileges can craft a specially designed URL that, when clicked by a victim, executes arbitrary JavaScript in the victim's browser context. This can lead to theft of session tokens, redirection to malicious sites, or execution of actions on behalf of the user within the portal environment. The vulnerability does not require the attacker to be authenticated, but user interaction (clicking the crafted link) is necessary for exploitation. The CVSS v3.1 base score is 5.4 (medium severity), reflecting network attack vector, low attack complexity, low privileges required, user interaction needed, and impact on confidentiality and integrity but no impact on availability. The vulnerability affects all versions up to and including 11.1, with no patch links currently provided. No known exploits are reported in the wild as of the publication date. Given the portal’s role in geographic information system (GIS) data sharing and collaboration, exploitation could compromise sensitive geospatial data or enable further attacks within an organization’s GIS infrastructure.

For European organizations, the impact of this vulnerability can be significant, especially for entities relying on Esri Portal for ArcGIS for critical GIS data management, such as government agencies, urban planning departments, environmental monitoring bodies, and utilities. Successful exploitation could lead to unauthorized disclosure of sensitive geospatial information, manipulation of GIS data integrity, or session hijacking, potentially disrupting decision-making processes or exposing confidential infrastructure details. Since the vulnerability requires user interaction, phishing or social engineering campaigns could be used to trick employees into clicking malicious links. The cross-site scripting flaw could also be leveraged as a foothold for further attacks within the network, including lateral movement or deployment of malware. Given the widespread use of Esri products in Europe, particularly in public sector and infrastructure domains, the vulnerability poses a moderate risk to confidentiality and integrity of critical data assets.

European organizations should implement the following specific mitigations: 1) Monitor Esri’s official channels for patches or updates addressing CVE-2024-25705 and apply them promptly once available. 2) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious input patterns or URLs targeting the portal’s web interface. 3) Conduct user awareness training focused on phishing and social engineering risks, emphasizing caution with unsolicited links related to GIS portals. 4) Restrict access to the Portal for ArcGIS Experience Builder interface to trusted networks or VPNs to reduce exposure to unauthenticated attackers. 5) Implement Content Security Policy (CSP) headers on the portal web server to limit the execution of unauthorized scripts. 6) Regularly audit portal logs for unusual access patterns or repeated failed attempts that may indicate exploitation attempts. 7) Use multi-factor authentication (MFA) for portal users to reduce the impact of session hijacking. 8) Segment GIS infrastructure from other critical systems to contain potential breaches.