# What is CVE-2020-3283? > CVE-2020-3283 is a high-severity flaw (CVSS 8.6) in Firepower Threat Defense from Cisco, published on 6 May 2020. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 2.0%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2020-3283 ## At a glance - **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle. - **Precursor Intelligence risk score:** 47 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** High (CVSS 8.6 out of 10) - **Known to be exploited:** No, not on the list of flaws known to be exploited today - **Chance of use in the next 30 days:** 2.0% (latest exploit-likelihood forecast) - **Published:** 6 May 2020 - **Record last updated:** 17 September 2021 - **Main product:** Firepower Threat Defense from Cisco - **Affected products:** 29 ## What is CVE-2020-3283? 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 take it offline. ### The official description A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) handler of Cisco Firepower Threat Defense (FTD) Software when running on the Cisco Firepower 1000 Series platform could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to a communication error between internal functions. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause a buffer underrun, which leads to a crash. The crash causes the affected device to reload. ### What kind of flaw is it? - CWE-787: Out-of-bounds Write - CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer ### 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 take it offline Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H` ## Is CVE-2020-3283 being exploited? Not that we know of It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.0%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 2.0%, 2.0%, 2.0%, 2.0%, 2.0%, 2.0%, 2.0%. ### Timeline - 6 May 2020: Published - 17 September 2021: Record last updated ### How Precursor Intelligence ranks it CVE-2020-3283 scores **47 out of 100 (Medium)**, with the action "Plan remediation". 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-2020-3283? The published record lists 29 products. Versions are as published: "6.4.0 to before 6.4.0.9" means from 6.4.0 up to, but not including, 6.4.0.9. - [Firepower Threat Defense](https://www.precursorintelligence.com/product/cisco/firepower_threat_defense) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 6.4.0 to before 6.4.0.9 - [ASA 5505 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5505_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5510 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5510_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5512-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5512-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5515-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5515-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5520 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5520_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5525-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5525-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5540 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5540_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5545-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5545-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5550 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5550_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5555-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5555-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5580 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5580_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5585-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5585-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.12(2.12), 9.13(0.33) - [ASA 5505](https://www.precursorintelligence.com/product/cisco/asa_5505) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5510](https://www.precursorintelligence.com/product/cisco/asa_5510) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5512-X](https://www.precursorintelligence.com/product/cisco/asa_5512-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5515-X](https://www.precursorintelligence.com/product/cisco/asa_5515-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5520](https://www.precursorintelligence.com/product/cisco/asa_5520) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5525-X](https://www.precursorintelligence.com/product/cisco/asa_5525-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5540](https://www.precursorintelligence.com/product/cisco/asa_5540) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5545-X](https://www.precursorintelligence.com/product/cisco/asa_5545-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5550](https://www.precursorintelligence.com/product/cisco/asa_5550) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5555-X](https://www.precursorintelligence.com/product/cisco/asa_5555-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5580](https://www.precursorintelligence.com/product/cisco/asa_5580) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5585-X](https://www.precursorintelligence.com/product/cisco/asa_5585-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1010](https://www.precursorintelligence.com/product/cisco/firepower_1010) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1020](https://www.precursorintelligence.com/product/cisco/firepower_1020) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1030](https://www.precursorintelligence.com/product/cisco/firepower_1030) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1040](https://www.precursorintelligence.com/product/cisco/firepower_1040) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified ## How do I fix CVE-2020-3283? 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. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood. ### References - [tools.cisco.com](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tls-dos-4v5nmWtZ) (Vendor advisory) ## Questions ### What is CVE-2020-3283? CVE-2020-3283 is a high-severity flaw in Firepower Threat Defense from Cisco, published on 6 May 2020. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline. ### How serious is CVE-2020-3283? It scores 8.6 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2020-3283 is 47 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle. ### Is CVE-2020-3283 being exploited? It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.0%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2020-3283 affect? For Firepower Threat Defense from Cisco: 6.4.0 to before 6.4.0.9. The record lists 29 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2020-3283? 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. ## Does CVE-2020-3283 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. Start free (no card, nothing to install): https://www.precursorintelligence.com/register Book a demo: https://www.precursorintelligence.com/contact