CVE-2025-34521: arcserve udp Cross-site Scripting

Vulnerability summary

CVE-2025-34521 is a medium (CVSS 5.4) Cross-site Scripting vulnerability in arcserve udp. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 11.3% of scored vulnerabilities.

Timeline

1. 27-08-2025
   PublishedVulnerability first disclosed.
2. 15-05-2026
   Last modifiedVulnerability information updated.

Description

A reflected cross-site scripting (XSS) vulnerability exists in the web interface of the Arcserve Unified Data Protection (UDP), where unsanitized user input is improperly reflected in HTTP responses. This flaw allows remote attackers with low privileges to craft malicious links that, when visited by another user, execute arbitrary JavaScript in the victim’s browser. Successful exploitation may lead to session hijacking, credential theft, or other client-side impacts. The vulnerability requires user interaction and occurs within a shared browser context. This vulnerability affects all UDP versions prior to 10.2. UDP 10.2 includes the necessary patches and requires no action. Versions 8.0 through 10.1 are supported and require either patch application or upgrade to 10.2. Versions 7.x and earlier are unsupported or out of maintenance and must be upgraded to 10.2 to remediate the issue.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.