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CVE-2025-20222VulnerabilityPublished

CVE-2025-20222: Cisco Firepower Threat Defense Software · Classic Buffer Overflow

Affects Cisco Firepower Threat Defense SoftwareSource CVE Database V5

0

Not known to be exploited · CVSS 8.6 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score
8.6High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 14 Aug 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

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

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Affected software

ProductAffectedFixed in
Cisco Cisco Firepower Threat Defense SoftwareAffected
  • =6.2.3
  • =6.2.3.9
  • =6.2.3.1
  • =6.2.3.2
  • =6.2.3.10
  • =6.4.0
  • =6.4.0.3
  • =6.4.0.4
  • =6.2.3.15
  • =6.2.3.6
  • =6.2.3.7
  • =6.2.3.12
  • =6.2.3.3
  • =6.2.3.11
  • =6.4.0.6
  • =6.2.3.13
  • =6.2.3.8
  • =6.2.3.4
  • =6.4.0.1
  • =6.2.3.5
  • =6.4.0.5
  • =6.2.3.14
  • =6.4.0.2
  • =6.4.0.8
  • =6.4.0.7
  • =6.6.0
  • =6.4.0.9
  • =6.2.3.16
  • =6.6.0.1
  • =6.6.1
  • =6.4.0.10
  • =6.4.0.11
  • =6.6.3
  • =6.6.4
  • =6.4.0.12
  • =7.0.0
  • =6.2.3.17
  • =7.0.0.1
  • =6.6.5
  • =7.0.1
  • =7.1.0
  • =6.4.0.13
  • =6.6.5.1
  • =6.2.3.18
  • =7.0.1.1
  • =6.4.0.14
  • =7.1.0.1
  • =6.6.5.2
  • =7.0.2
  • =6.4.0.15
  • =7.2.0
  • =7.0.2.1
  • =7.0.3
  • =6.6.7
  • =7.2.0.1
  • =7.0.4
  • =7.2.1
  • =7.0.5
  • =6.4.0.16
  • =7.3.0
  • =7.2.2
  • =6.6.7.1
  • =7.2.3
  • =7.3.1
  • =7.1.0.3
  • =7.2.4
  • =7.0.6
  • =7.2.5
  • =7.2.4.1
  • =7.3.1.1
  • =6.4.0.17
  • =7.0.6.1
  • =7.2.5.1
  • =7.4.1
  • =7.2.6
  • =7.0.6.2
  • =7.4.1.1
  • =6.6.7.2
  • =6.4.0.18
  • =7.2.7
  • =7.2.5.2
  • =7.3.1.2
  • =7.2.8
  • =7.4.2
  • =7.2.8.1
  • =7.0.6.3
  • =7.4.2.1
  • =7.2.9
Fixed in–

AI-suggested

To mitigate this vulnerability effectively, European organizations should prioritize the following actions: 1) Immediate identification and inventory of all Cisco ASA and FTD devices running affected software versions, with special attention to those configured with IPsec VPN and RADIUS proxy features. 2) Apply Cisco's official patches or software updates as soon as they become available, ensuring that devices are upgraded to versions that address the buffer overflow issue. 3) In the interim, consider disabling IPv6 support on IPsec VPN interfaces if IPv6 is not required, to reduce the attack surface. 4) Implement network-level filtering to restrict or monitor IPv6 traffic entering VPN endpoints, using intrusion detection/prevention systems to detect anomalous packet patterns. 5) Enhance logging and monitoring for unusual device reloads or VPN disruptions that may indicate exploitation attempts. 6) Conduct regular vulnerability assessments and penetration testing focused on VPN infrastructure to identify and remediate potential weaknesses. 7) Develop and test incident response plans specifically for network device DoS scenarios to minimize operational impact. These measures go beyond generic advice by focusing on IPv6 traffic controls, device-specific patch management, and proactive detection tailored to the vulnerability's characteristics.

Description

A vulnerability in the RADIUS proxy feature for the IPsec VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper processing of IPv6 packets. An attacker could exploit this vulnerability by sending IPv6 packets over an IPsec VPN connection to an affected device. A successful exploit could allow the attacker to trigger a reload of the device, resulting in a DoS condition.

References

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