# Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense: 2 exploited vulnerabilities (CVE-2025-20333, CVE-2025-20362) · pwn.watch

> CVE-2025-20333: Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a buffer overflow vulnerability that allows for remote code execution. This vulnerability could be chained with CVE-2025-20362. CVE-2025-20362: Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a missing authorization vulnerability. This vulnerability could be chained with CVE-2025-20333. Added to CISA KEV on 2025-09-25.

Page: https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333 · generated 2026-10-22T20:45:43.249Z

## Status
- Severity: critical · status: closed · patch: patched
- Product: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense
- Started: 2025-09-25 · closed: 2025-09-25
- CVEs: CVE-2025-20333, CVE-2025-20362
- Affected: See vendor advisory / CISA notes (versions not always listed in KEV feed)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333/feed.xml
- JSON Feed: https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333.json
- This file: https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333/llms.txt

## Updates (newest first)
- 2025-09-25: CISA added CVE-2025-20333 to the KEV catalog (due 2025-09-26).
- 2025-09-25: CISA added CVE-2025-20362 to the KEV catalog (due 2025-09-26).

## Fix brief
# Security brief: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense: 2 exploited vulnerabilities (CVE-2025-20333, CVE-2025-20362)

Source: https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333 · status: closed (closed Sep 25, 2025) · severity: critical · updated Sep 25, 2025

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
CVE-2025-20333: Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a buffer overflow vulnerability that allows for remote code execution. This vulnerability could be chained with CVE-2025-20362. CVE-2025-20362: Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a missing authorization vulnerability. This vulnerability could be chained with CVE-2025-20333. Added to CISA KEV on 2025-09-25.

Severity detail: CVSS 9.9 (CNA, v3.1); actively exploited (CISA KEV)

- Product: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense
- CVE / advisory ids: CVE-2025-20333, CVE-2025-20362

## Affected versions
- See vendor advisory / CISA notes (versions not always listed in KEV feed)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- Sep 25, 2025: CISA added CVE-2025-20333 to the KEV catalog (due 2025-09-26).
- Sep 25, 2025: CISA added CVE-2025-20362 to the KEV catalog (due 2025-09-26).

## Advisories
- [CISA guidance: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense](https://www.cisa.gov/news-events/directives/ed-25-03-identify-and-mitigate-potential-compromise-cisco-devices) (CISA)
- [CISA guidance: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense](https://www.cisa.gov/news-events/directives/supplemental-direction-ed-25-03-core-dump-and-hunt-instructions) (CISA)
- [CISA guidance: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense](https://www.cisa.gov/eviction-strategies-tool/create-from-template) (CISA)
- [Cisco advisory: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense](https://sec.cloudapps.cisco.com/security/center/resources/asa_ftd_continued_attacks) (Cisco)
- [Cisco advisory: Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense](https://sec.cloudapps.cisco.com/security/center/private/resources/asa_ftd_continued_attacks#Details) (Cisco)
- [NVD: CVE-2025-20333](https://nvd.nist.gov/vuln/detail/CVE-2025-20333) (NVD)
- [NVD: CVE-2025-20362](https://nvd.nist.gov/vuln/detail/CVE-2025-20362) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from CISA KEV JSON feed catalogVersion 2026.10.21. CVSS from the CVE record (cvelistV5). Exact affected/fixed version strings are not always in the KEV record; verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier; many entries are older CVEs newly confirmed as exploited in 2025).

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Machine-readable: https://pwn.watch/i/cisco-secure-firewall-adaptive-security-appliance-and-s-cve-2025-20333.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.