CVE-2025-41255Public exploitNetwork attack vector

Trust bypass via unrestricted root certificate installation

Published Jun 25, 2025 · Updated Jun 25, 2025

Incorrect privilege assignment in Cyberduck 9.1.6 and earlier and Mountain Duck 4.17.5 and earlier allows attackers to subvert certificate trust. When a user permanently accepts an unknown TLS certificate, the clients place it in the current user's Trusted Root Certification Authorities store with all intended purposes instead of pinning only its fingerprint for that service. Exploitation requires the user to connect to an attacker-controlled TLS service and approve permanent trust, after which other applications can trust the certificate for server authentication, code signing, or man-in-the-middle attacks.

CVSS severity8.0
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect privilege assignment in Cyberduck 9.1.6 and earlier and Mountain Duck 4.17.5 and earlier allows attackers to subvert certificate trust. When a user permanently accepts an unknown TLS certificate, the clients place it in the current user's Trusted Root Certification Authorities store with all intended purposes instead of pinning only its fingerprint for that service. Exploitation requires the user to connect to an attacker-controlled TLS service and approve permanent trust, after which other applications can trust the certificate for server authentication, code signing, or man-in-the-middle attacks.

The record

CVE
CVE-2025-41255
Published
Jun 25, 2025
Updated
Jun 25, 2025
Vendor
iterate GmbH
Product
Mountain Duck
Classifications
CWE-266, T1553.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=4.17.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

iterate GmbH · Mountain Duckversion=0 <=4.17.5
iterate GmbH · Cyberduckversion=0 <=9.1.6

Published CVSS scores

8.0SBA ResearchCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-266Incorrect Privilege Assignment
T1553.004Install Root Certificate

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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