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CVE-2025-20333VulnerabilityPublished Updated

Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software VPN Web Server

Affects CiscoSource GCVE Database

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Authoritative record:CVE-2025-20333· Critical 9.9

Exploited in the wild · KEV due 26 Sep 2025 : apply the vendor's fix or mitigations to Cisco now.

Data as of 4 Nov 2026, 18:29 UTC

CVSS 3.1 base score
9.9Critical
How severe the flaw is on the 0–10 CVSS scale.
KEV deadline
 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 25 Sep 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: evidence found.

    Listed in CISA KEV the same day as disclosure

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by Cisco Systems, Inc.

    , 350 days before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. In Threat Radar

    record ingested

    , 3 minutes after disclosure

  4. , the same day as disclosure

  5. KEV remediation due

    US federal deadline

    , 1 day after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 4 Nov 2026.

What to do

Affected software

ProductAffectedFixed in
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) SoftwareAffected
  • 9.8.1 – 9.22.1.2
206 affected builds
Fixed in–
CiscoCisco Secure Firewall Threat Defense (FTD) SoftwareAffected
  • 6.2.3 – 7.6.0
94 affected builds
Fixed in–

Check the firmware or software version for Cisco in the device's admin interface against the vendor advisory.

AI-suggested

Administrators should review their VPN configurations for the listed vulnerable features and consider disabling or modifying them until a fix is applied.

Description

CVE-2025-20333 is a vulnerability affecting Cisco Secure Firewall ASA Software and Cisco Secure Firewall Threat Defense (FTD) Software when certain remote access VPN features are enabled. The vulnerability involves SSL listen sockets being enabled under specific configurations related to AnyConnect IKEv2 Remote Access, Mobile User Security, and SSL VPN features. The affected versions are 9.8, 9.8.1, and 9.8.1.5. This issue requires the presence of vulnerable configurations to be exploitable.

References

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