CVE-2025-59695

Persistent firmware compromise via unauthenticated cosmoupgrade

Published Dec 2, 2025 · Updated Dec 2, 2025

Unauthenticated firmware updates in Entrust nShield appliances through 13.6.11, or 13.7, allow local users with OS root access to alter CMB firmware. The cosmoupgrade utility checks only the firmware version and CRC, accepting arbitrary images without authenticating their origin or integrity. The OS-root gate limits exploitation to a previously compromised appliance, but the resulting CMB backdoor can persist undetected.

CVSS severity9.8
Critical
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unauthenticated firmware updates in Entrust nShield appliances through 13.6.11, or 13.7, allow local users with OS root access to alter CMB firmware. The cosmoupgrade utility checks only the firmware version and CRC, accepting arbitrary images without authenticating their origin or integrity. The OS-root gate limits exploitation to a previously compromised appliance, but the resulting CMB backdoor can persist undetected.

The record

CVE
CVE-2025-59695
Published
Dec 2, 2025
Updated
Dec 2, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-306, T1495
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1495Firmware Corruption

Public exploit references

No public exploit references are available in this record.

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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