CVE-2025-34520CRITICAL 9.8EPSS p26.4%

CVE-2025-34520CVE-2025-34520

Description

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.

Scoring

CVSS 3.19.8 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS0.35% probability of exploitation · percentile 26.4% · 2026-06-18T12:00:27Z
Published2025-08-27
Last modified2025-09-09

Underlying weaknesses· 1

CWE-288

References

  1. https://support.arcserve.com/s/article/Important-Security-Bulletin-Must-read-for-all-Arcserve-UDP-customers-on-all-versions

1

TypeTargetConfidenceTier
WeaknessAuthentication Bypass Using an Alternate Path or Channelcwe-2880%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

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Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.