# Cisco ASA and FTD Denial-of-Service · pwn.watch

> Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain a missing release of resource after effective lifetime vulnerability that could allow an unauthenticated, remote attacker to cause a denial-of-service (DoS) of the RAVPN service. Added to the CISA KEV catalog on 2024-10-24.

Page: https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481 · generated 2026-10-23T00:16:28.879Z

## Status
- Severity: medium · status: closed · patch: patched
- Product: Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
- Started: 2024-10-23 · closed: 2024-10-24
- CVEs: CVE-2024-20481
- Affected: See vendor advisory (versions are not listed in the KEV record)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481/feed.xml
- JSON Feed: https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481.json
- This file: https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481/llms.txt

## Updates (newest first)
- 2024-10-24: CISA added CVE-2024-20481 to the KEV catalog (federal deadline 2024-11-14) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)
- 2024-10-23: CVE-2024-20481 published (https://nvd.nist.gov/vuln/detail/CVE-2024-20481)

## Fix brief
# Security brief: Cisco ASA and FTD Denial-of-Service

Source: https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481 · status: closed (closed Oct 24, 2024) · severity: medium · updated Oct 24, 2024

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

## What it is
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain a missing release of resource after effective lifetime vulnerability that could allow an unauthenticated, remote attacker to cause a denial-of-service (DoS) of the RAVPN service. Added to the CISA KEV catalog on 2024-10-24.

Severity detail: CVSS 5.8 (v3.1, CNA), actively exploited (CISA KEV)

- Product: Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
- CVE / advisory ids: CVE-2024-20481

## Affected versions
- See vendor advisory (versions are not listed in the KEV record)

## 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
- Oct 24, 2024: CISA added CVE-2024-20481 to the KEV catalog (federal deadline 2024-11-14)
- Oct 23, 2024: CVE-2024-20481 published

## Advisories
- [Cisco advisory: CVE-2024-20481](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-bf-dos-vDZhLqrW) (Cisco)
- [NVD: CVE-2024-20481](https://nvd.nist.gov/vuln/detail/CVE-2024-20481) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from the CISA KEV JSON feed (catalogVersion 2026.10.21); CVSS from the CVE record (cveawg.mitre.org). startedAt is the CVE publication date when it fell in 2024 before the KEV listing, else the KEV dateAdded; exploitation may have begun earlier. closedAt is the KEV listing date (a fix or mitigation was available then unless noted).

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Machine-readable: https://pwn.watch/i/cisco-adaptive-security-appliance-asa-and-firepowe-cve-2024-20481.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.