Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software VPN Web Server
Affects CiscoSource GCVE Database
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
- 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:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 25 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV the same day as disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Cisco Systems, Inc.
, 350 days before disclosure
CVE published
on cve.org
, t = 0
In Threat Radar
record ingested
, 3 minutes after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, the same day as disclosure
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
| Product | Affected | Fixed in |
|---|---|---|
| CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software | Affected
| Fixed in– |
| CiscoCisco Secure Firewall Threat Defense (FTD) Software | Affected
| 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
- sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webvpn-z5xP8EUB (opens in a new tab)
- sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html (opens in a new tab)
- sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks (opens in a new tab)
- software.cisco.com/download/specialrelease/5c390a2391d7c51421843b43e70e8373 (opens in a new tab)
- software.cisco.com/download/specialrelease/29ca8c3a3cc367a4c86144da9f77dabf (opens in a new tab)
- sec.cloudapps.cisco.com/security/center/softwarechecker.x (opens in a new tab)
- sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html (opens in a new tab)
- cisco.com/c/en/us/td/docs/security/asa/asa920/configuration/firewall/asa-920-firewall-config/conns-threat.html (opens in a new tab)
- cisco.com/web/about/security/psirt/security_vulnerability_policy.html (opens in a new tab)
- cisco.com/c/en/us/support/index.html (opens in a new tab)
- cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html (opens in a new tab)
- sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html (opens in a new tab)
- cisco.com/go/psirt (opens in a new tab)