# What is CVE-2020-1472? > CVE-2020-1472 is a medium-severity flaw (CVSS 5.5) in Windows Server 1903 from Microsoft, published on 17 August 2020. 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 over 99%. If you run an affected version, patch it first. Canonical page: https://www.precursorintelligence.com/what-is/cve-2020-1472 ## 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:** 90 out of 100 (Critical); action: Emergency patch. Kept up to date as the evidence changes. - **Severity:** Medium (CVSS 5.5 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:** over 99% (latest exploit-likelihood forecast) - **Published:** 17 August 2020 - **Record last updated:** 7 March 2025 - **Main product:** Windows Server 1903 from Microsoft - **Affected products:** 15 ## What is CVE-2020-1472? In plain terms An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data. ### The official description An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller, using the Netlogon Remote Protocol (MS-NRPC). An attacker who successfully exploited the vulnerability could run a specially crafted application on a device on the network. To exploit the vulnerability, an unauthenticated attacker would be required to use MS-NRPC to connect to a domain controller to obtain domain administrator access. Microsoft is addressing the vulnerability in a phased two-part rollout. These updates address the vulnerability by modifying how Netlogon handles the usage of Netlogon secure channels. For guidelines on how to manage the changes required for this vulnerability and more information on the phased rollout, see How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472 (updated September 28, 2020). When the second phase of Windows updates become available in Q1 2021, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this advisory. See Microsoft Technical Security Notifications. ### What kind of flaw is it? - Unknown: Unknown ### How an attack on it works - Where an attacker can be: Already on the device - How hard it is to pull off: Easy: no special conditions - Login needed first: An ordinary user account - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can read data Severity vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N` ## Is CVE-2020-1472 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 over 99%. Exploit likelihood over the last 7 days: >99%, >99%, >99%, >99%, >99%, >99%, >99%. ### Timeline - 17 August 2020: Published - 7 March 2025: Record last updated ### How Precursor Intelligence ranks it CVE-2020-1472 scores **90 out of 100 (Critical)**, 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-2020-1472? The published record lists 15 products. Versions are as published: "before 4.10.18" means every version up to, but not including, 4.10.18. - [Windows Server 1903](https://www.precursorintelligence.com/product/microsoft/windows_server_1903) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): all versions - [Ubuntu Linux](https://www.precursorintelligence.com/product/canonical/ubuntu_linux) by [Canonical](https://www.precursorintelligence.com/vendors/canonical) (Operating system): 14.04, 16.04, 18.04, 20.04 - [Fedora](https://www.precursorintelligence.com/product/fedoraproject/fedora) by [Fedoraproject](https://www.precursorintelligence.com/vendors/fedoraproject) (Operating system): 31, 32, 33 - [Samba](https://www.precursorintelligence.com/product/samba/samba) by [Samba](https://www.precursorintelligence.com/vendors/samba) (Application): before 4.10.18, 4.11.0 to before 4.11.13, 4.12.0 to before 4.12.7 - [Leap](https://www.precursorintelligence.com/product/opensuse/leap) by [Opensuse](https://www.precursorintelligence.com/vendors/opensuse) (Operating system): 15.1, 15.2 - [Debian Linux](https://www.precursorintelligence.com/product/debian/debian_linux) by [Debian](https://www.precursorintelligence.com/vendors/debian) (Operating system): 9.0 - [Directory Server](https://www.precursorintelligence.com/product/synology/directory_server) by [Synology](https://www.precursorintelligence.com/vendors/synology) (Application): before 4.4.5-0101 - [Windows Server 1909](https://www.precursorintelligence.com/product/microsoft/windows_server_1909) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): all versions - [Windows Server 2004](https://www.precursorintelligence.com/product/microsoft/windows_server_2004) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified - [Windows Server 2008](https://www.precursorintelligence.com/product/microsoft/windows_server_2008) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): r2-sp1 - [Windows Server 2012](https://www.precursorintelligence.com/product/microsoft/windows_server_2012) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): r2 - [Windows Server 2016](https://www.precursorintelligence.com/product/microsoft/windows_server_2016) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified - [Windows Server 2019](https://www.precursorintelligence.com/product/microsoft/windows_server_2019) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified - [Windows Server 20H2](https://www.precursorintelligence.com/product/microsoft/windows_server_20h2) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified - [Zfs Storage Appliance Kit](https://www.precursorintelligence.com/product/oracle/zfs_storage_appliance_kit) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 8.8 ## How do I fix CVE-2020-1472? 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 advisories and patch notes 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 - [portal.msrc.microsoft.com](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1472) (Patch, Vendor advisory) - [oracle.com](https://www.oracle.com/security-alerts/cpuApr2021.html) (Patch, Third-party advisory) - [lists.opensuse.org](http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00080.html) (Mailing list, Third-party advisory) - [lists.opensuse.org](http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00086.html) (Mailing list, Third-party advisory) - [packetstormsecurity.com](http://packetstormsecurity.com/files/159190/Zerologon-Proof-Of-Concept.html) (Third-party advisory, Vulnerability database) - [packetstormsecurity.com](http://packetstormsecurity.com/files/160127/Zerologon-Netlogon-Privilege-Escalation.html) (Exploit, Third-party advisory, Vulnerability database) - [openwall.com](http://www.openwall.com/lists/oss-security/2020/09/17/2) (Mailing list, Third-party advisory) - [lists.debian.org](https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html) (Mailing list, Third-party advisory) - [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H4OTFBL6YDVFH2TBJFJIE4FMHPJEEJK3/) (Mailing list, Third-party advisory) - [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ST6X3A2XXYMGD4INR26DQ4FP4QSM753B/) (Mailing list, Third-party advisory) - [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TAPQQZZAT4TG3XVRTAFV2Y3S7OAHFBUP/) (Mailing list, Third-party advisory) - [security.gentoo.org](https://security.gentoo.org/glsa/202012-24) (Third-party advisory) - [usn.ubuntu.com](https://usn.ubuntu.com/4510-1/) (Third-party advisory) - [usn.ubuntu.com](https://usn.ubuntu.com/4510-2/) (Third-party advisory) - [usn.ubuntu.com](https://usn.ubuntu.com/4559-1/) (Third-party advisory) - [kb.cert.org](https://www.kb.cert.org/vuls/id/490028) (Third-party advisory, Government resource) - [synology.com](https://www.synology.com/security/advisory/Synology_SA_20_21) (Third-party advisory) ## Questions ### What is CVE-2020-1472? CVE-2020-1472 is a medium-severity flaw in Windows Server 1903 from Microsoft, published on 17 August 2020. An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data. ### How serious is CVE-2020-1472? It scores 5.5 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2020-1472 is 90 out of 100, which is Critical. 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-2020-1472 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 over 99%. ### Which versions does CVE-2020-1472 affect? For Windows Server 1903 from Microsoft: all versions. The record lists 15 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2020-1472? 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-2020-1472 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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