# What is CVE-2024-20481? > CVE-2024-20481 is a medium-severity flaw (CVSS 5.8) in Secure Firewall Threat Defense from Cisco, published on 23 October 2024. It is on the list of flaws known to be exploited, so criminals are already using it. The latest forecast puts its chance of use in the next 30 days at 16%. If you run an affected version, patch it first. Canonical page: https://www.precursorintelligence.com/what-is/cve-2024-20481 ## At a glance - **Verdict:** Fix this now. Attackers are using this flaw today. If you run an affected version, it goes to the top of your list. - **Precursor Intelligence risk score:** 71 out of 100 (High); action: Emergency patch. Kept up to date as the evidence changes. - **Severity:** Medium (CVSS 5.8 out of 10) - **Known to be exploited:** Yes, it is on the government list of flaws known to be exploited - **Chance of use in the next 30 days:** 16% (latest exploit-likelihood forecast) - **Published:** 23 October 2024 - **Record last updated:** 11 August 2026 - **Main product:** Secure Firewall Threat Defense from Cisco - **Affected products:** 2 ## What is CVE-2024-20481? In plain terms It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can slow it down. ### The official description A vulnerability in the Remote Access VPN (RAVPN) service of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) of the RAVPN service. This vulnerability is due to resource exhaustion. An attacker could exploit this vulnerability by sending a large number of VPN authentication requests to an affected device. A successful exploit could allow the attacker to exhaust resources, resulting in a DoS of the RAVPN service on the affected device. Depending on the impact of the attack, a reload of the device may be required to restore the RAVPN service. Services that are not related to VPN are not affected. Cisco Talos discussed these attacks in the blog post Large-scale brute-force activity targeting VPNs, SSH services with commonly used login credentials. ### What kind of flaw is it? - CWE-772: Missing Release of Resource after Effective Lifetime ### How an attack on it works - Where an attacker can be: Anywhere on the internet - How hard it is to pull off: Easy: no special conditions - Login needed first: No login needed - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can slow it down Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L` ## Is CVE-2024-20481 being exploited? Yes Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 16%. Exploit likelihood over the last 7 days: 16%, 16%, 16%, 16%, 16%, 16%, 16%. ### Timeline - 23 October 2024: Published - 11 August 2026: Record last updated ### How Precursor Intelligence ranks it CVE-2024-20481 scores **71 out of 100 (High)**, with the action "Emergency patch". Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less: - Evidence it is being exploited: biggest factor - How severe it is: strong factor - How widely exposed it is: smaller factor - Threat activity around it: smaller factor 85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it. ## Who is affected by CVE-2024-20481? The published record lists 2 products. - [Secure Firewall Threat Defense](https://www.precursorintelligence.com/product/cisco/secure_firewall_threat_defense) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 6.2.3, 6.2.3.1, 6.2.3.2, 6.2.3.3, 6.2.3.4, 6.2.3.5, 6.2.3.6, 6.2.3.7, 6.2.3.8, 6.2.3.9, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15, 6.2.3.16, 6.2.3.17, 6.2.3.18, 6.4.0, 6.4.0.1, 6.4.0.2, 6.4.0.3, 6.4.0.4, 6.4.0.5, 6.4.0.6, 6.4.0.7, 6.4.0.8, 6.4.0.9, 6.4.0.10, 6.4.0.11, 6.4.0.12, 6.4.0.13, 6.4.0.14, 6.4.0.15, 6.4.0.16, 6.4.0.17, 6.4.0.18, 6.6.0, 6.6.0.1 and 50 more - [Adaptive Security Appliance Software](https://www.precursorintelligence.com/product/cisco/adaptive_security_appliance_software) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.8.1, 9.8.1.5, 9.8.1.7, 9.8.2, 9.8.2.8, 9.8.2.14, 9.8.2.15, 9.8.2.17, 9.8.2.20, 9.8.2.24, 9.8.2.26, 9.8.2.28, 9.8.2.33, 9.8.2.35, 9.8.2.38, 9.8.2.45, 9.8.3, 9.8.3.8, 9.8.3.11, 9.8.3.14, 9.8.3.16, 9.8.3.18, 9.8.3.21, 9.8.3.26, 9.8.3.29, 9.8.4, 9.8.4.3, 9.8.4.7, 9.8.4.8, 9.8.4.10, 9.8.4.12, 9.8.4.15, 9.8.4.17, 9.8.4.20, 9.8.4.22, 9.8.4.25, 9.8.4.26, 9.8.4.29, 9.8.4.32, 9.8.4.33 and 159 more ## How do I fix CVE-2024-20481? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list. 2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list. 3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in. 4. **Check it wasn’t used before you patched.** Because criminals are already using this flaw, look for signs of a break-in on affected systems using the vendor’s guidance. ### References - [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-bf-dos-vDZhLqrW) (Vendor advisory) - [cisa.gov](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-20481) (Government resource) ## Questions ### What is CVE-2024-20481? CVE-2024-20481 is a medium-severity flaw in Secure Firewall Threat Defense from Cisco, published on 23 October 2024. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can slow it down. ### How serious is CVE-2024-20481? It scores 5.8 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2024-20481 is 71 out of 100, which is High. Its action is "Emergency patch". Attackers are using this flaw today. If you run an affected version, it goes to the top of your list. ### Is CVE-2024-20481 being exploited? Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 16%. ### Which versions does CVE-2024-20481 affect? For Secure Firewall Threat Defense from Cisco: 6.2.3, 6.2.3.1, 6.2.3.2, 6.2.3.3, 6.2.3.4, 6.2.3.5 and 84 more. The record lists 2 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2024-20481? Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. Because criminals are already using it, also check affected systems for signs of a break-in. ## Does CVE-2024-20481 affect you? Precursor Intelligence keeps checking for you: - **Tell us what you run.** Pick your software from a list, or let us work it out from your website. - **We match it to every flaw.** Over 400,000 published flaws, checked against your list. - **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it. - **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools. 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