# What is CVE-2022-20866? > CVE-2022-20866 is a high-severity flaw (CVSS 7.5) in Firepower Threat Defense from Cisco, published on 10 August 2022. 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 18%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2022-20866 ## At a glance - **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month. - **Precursor Intelligence risk score:** 59 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** High (CVSS 7.5 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:** 18% (latest exploit-likelihood forecast) - **Published:** 10 August 2022 - **Record last updated:** 7 November 2023 - **Main product:** Firepower Threat Defense from Cisco - **Affected products:** 34 ## What is CVE-2022-20866? 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 read data. ### The official description A vulnerability in the handling of RSA keys on devices running Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to retrieve an RSA private key. This vulnerability is due to a logic error when the RSA key is stored in memory on a hardware platform that performs hardware-based cryptography. An attacker could exploit this vulnerability by using a Lenstra side-channel attack against the targeted device. A successful exploit could allow the attacker to retrieve the RSA private key. The following conditions may be observed on an affected device: This vulnerability will apply to approximately 5 percent of the RSA keys on a device that is running a vulnerable release of Cisco ASA Software or Cisco FTD Software; not all RSA keys are expected to be affected due to mathematical calculations applied to the RSA key. The RSA key could be valid but have specific characteristics that make it vulnerable to the potential leak of the RSA private key. If an attacker obtains the RSA private key, they could use the key to impersonate a device that is running Cisco ASA Software or Cisco FTD Software or to decrypt the device traffic. See the Indicators of Compromise section for more information on the detection of this type of RSA key. The RSA key could be malformed and invalid. A malformed RSA key is not functional, and a TLS client connection to a device that is running Cisco ASA Software or Cisco FTD Software that uses the malformed RSA key will result in a TLS signature failure, which means a vulnerable software release created an invalid RSA signature that failed verification. If an attacker obtains the RSA private key, they could use the key to impersonate a device that is running Cisco ASA Software or Cisco FTD Software or to decrypt the device traffic. ### What kind of flaw is it? - CWE-203: Observable Discrepancy ### 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 read data Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N` ## Is CVE-2022-20866 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 18%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 18%, 18%, 18%, 18%, 18%, 18%, 18%. ### Timeline - 10 August 2022: Published - 7 November 2023: Record last updated ### How Precursor Intelligence ranks it CVE-2022-20866 scores **59 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-2022-20866? The published record lists 34 products. Versions are as published: "7.0.0 to before 7.0.4" means from 7.0.0 up to, but not including, 7.0.4. - [Firepower Threat Defense](https://www.precursorintelligence.com/product/cisco/firepower_threat_defense) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 7.0.0 to before 7.0.4, 7.1.0 to before 7.2.0.1 - [Adaptive Security Appliance Software](https://www.precursorintelligence.com/product/cisco/adaptive_security_appliance_software) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 9.16.0 to before 9.16.3.19, 9.17.0 to before 9.17.1.13, 9.18.0 to before 9.18.2 - [ASA 5506-X](https://www.precursorintelligence.com/product/cisco/asa_5506-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5506h-X](https://www.precursorintelligence.com/product/cisco/asa_5506h-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5506w-X](https://www.precursorintelligence.com/product/cisco/asa_5506w-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5508-X](https://www.precursorintelligence.com/product/cisco/asa_5508-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5516-X](https://www.precursorintelligence.com/product/cisco/asa_5516-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1000](https://www.precursorintelligence.com/product/cisco/firepower_1000) 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 - [Firepower 1120](https://www.precursorintelligence.com/product/cisco/firepower_1120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1140](https://www.precursorintelligence.com/product/cisco/firepower_1140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 1150](https://www.precursorintelligence.com/product/cisco/firepower_1150) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 2100](https://www.precursorintelligence.com/product/cisco/firepower_2100) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 2110](https://www.precursorintelligence.com/product/cisco/firepower_2110) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 2120](https://www.precursorintelligence.com/product/cisco/firepower_2120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 2130](https://www.precursorintelligence.com/product/cisco/firepower_2130) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 2140](https://www.precursorintelligence.com/product/cisco/firepower_2140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4100](https://www.precursorintelligence.com/product/cisco/firepower_4100) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4110](https://www.precursorintelligence.com/product/cisco/firepower_4110) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4112](https://www.precursorintelligence.com/product/cisco/firepower_4112) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4115](https://www.precursorintelligence.com/product/cisco/firepower_4115) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4120](https://www.precursorintelligence.com/product/cisco/firepower_4120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4125](https://www.precursorintelligence.com/product/cisco/firepower_4125) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4140](https://www.precursorintelligence.com/product/cisco/firepower_4140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4145](https://www.precursorintelligence.com/product/cisco/firepower_4145) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 4150](https://www.precursorintelligence.com/product/cisco/firepower_4150) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Firepower 9300](https://www.precursorintelligence.com/product/cisco/firepower_9300) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Secure Firewall 3110](https://www.precursorintelligence.com/product/cisco/secure_firewall_3110) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Secure Firewall 3120](https://www.precursorintelligence.com/product/cisco/secure_firewall_3120) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Secure Firewall 3130](https://www.precursorintelligence.com/product/cisco/secure_firewall_3130) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Secure Firewall 3140](https://www.precursorintelligence.com/product/cisco/secure_firewall_3140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified ## How do I fix CVE-2022-20866? 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-asaftd-rsa-key-leak-Ms7UEfZz) (Vendor advisory) ## Questions ### What is CVE-2022-20866? CVE-2022-20866 is a high-severity flaw in Firepower Threat Defense from Cisco, published on 10 August 2022. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data. ### How serious is CVE-2022-20866? It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2022-20866 is 59 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month. ### Is CVE-2022-20866 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 18%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2022-20866 affect? For Firepower Threat Defense from Cisco: 7.0.0 to before 7.0.4, 7.1.0 to before 7.2.0.1. The record lists 34 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2022-20866? 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-2022-20866 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