# What is CVE-2020-3125? > CVE-2020-3125 is a critical-severity flaw (CVSS 9.8) in ASA 5505 Firmware 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 2.4%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2020-3125 ## 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:** 54 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** Critical (CVSS 9.8 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:** 2.4% (latest exploit-likelihood forecast) - **Published:** 6 May 2020 - **Record last updated:** 16 August 2023 - **Main product:** ASA 5505 Firmware from Cisco - **Affected products:** 25 ## What is CVE-2020-3125? 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, change data and take it offline. ### The official description A vulnerability in the Kerberos authentication feature of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to impersonate the Kerberos key distribution center (KDC) and bypass authentication on an affected device that is configured to perform Kerberos authentication for VPN or local device access. The vulnerability is due to insufficient identity verification of the KDC when a successful authentication response is received. An attacker could exploit this vulnerability by spoofing the KDC server response to the ASA device. This malicious response would not have been authenticated by the KDC. A successful attack could allow an attacker to bypass Kerberos authentication. ### What kind of flaw is it? - CWE-287: Improper Authentication ### 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, change data and take it offline Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` ## Is CVE-2020-3125 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 2.4%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 2.4%, 2.4%, 2.4%, 2.4%, 2.4%, 2.4%, 2.4%. ### Timeline - 6 May 2020: Published - 16 August 2023: Record last updated ### How Precursor Intelligence ranks it CVE-2020-3125 scores **54 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-2020-3125? The published record lists 25 products. Versions are as published: "9.8 to before 9.8.4.15" means from 9.8 up to, but not including, 9.8.4.15. - [ASA 5505 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5505_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [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 to before 9.8.4.15, 9.9 to before 9.9.2.66, 9.10 to before 9.10.1.37, 9.12 to before 9.12.3.2, 9.13 to before 9.13.1.7 - [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 5510 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5510_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [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 5512-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5512-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [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 5515-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5515-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [ASA 5520](https://www.precursorintelligence.com/product/cisco/asa_5520) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5520 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5520_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [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 5525-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5525-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [ASA 5540](https://www.precursorintelligence.com/product/cisco/asa_5540) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5540 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5540_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [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 5545-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5545-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [ASA 5550](https://www.precursorintelligence.com/product/cisco/asa_5550) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5550 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5550_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [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 5555-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5555-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [ASA 5580](https://www.precursorintelligence.com/product/cisco/asa_5580) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5580 Firmware](https://www.precursorintelligence.com/product/cisco/asa_5580_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) - [ASA 5585-X](https://www.precursorintelligence.com/product/cisco/asa_5585-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [ASA 5585-X Firmware](https://www.precursorintelligence.com/product/cisco/asa_5585-x_firmware) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.10(1.220) ## How do I fix CVE-2020-3125? 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-asa-kerberos-bypass-96Gghe2sS) (Vendor advisory) ## Questions ### What is CVE-2020-3125? CVE-2020-3125 is a critical-severity flaw in ASA 5505 Firmware 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 read data, change data and take it offline. ### How serious is CVE-2020-3125? It scores 9.8 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2020-3125 is 54 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-2020-3125 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 2.4%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2020-3125 affect? For ASA 5505 Firmware from Cisco: 9.10(1.220). The record lists 25 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2020-3125? 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-2020-3125 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