Vulnerability in Arcserve Udp

CVE-2025-34520

An authentication bypass vulnerability in Arcserve Unified Data Protection (UDP) allows unauthenticated attackers to gain unauthorized access to protected functionality or user accounts. By manipulating specific request parameters or exploiting a logic flaw, an attacker can bypass login mechanisms without valid credentials and access administrator-level features. 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.

EPSS: 0.004 (29.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-34520?
CVE-2025-34520 is a critical-severity vulnerability in Arcserve Udp, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 9.8/10. Published 2025-08-27.
How severe is CVE-2025-34520?
Critical severity. CVSS v3 base score is 9.8 out of 10.