# What is CVE-2023-20867? > CVE-2023-20867 is a low-severity flaw (CVSS 3.9) in Tools from VMware, published on 13 June 2023. 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 14%. If you run an affected version, patch it first. Canonical page: https://www.precursorintelligence.com/what-is/cve-2023-20867 ## 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:** 74 out of 100 (High); action: Emergency patch. Kept up to date as the evidence changes. - **Severity:** Low (CVSS 3.9 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:** 14% (latest exploit-likelihood forecast) - **Published:** 13 June 2023 - **Record last updated:** 28 October 2025 - **Main product:** Tools from VMware - **Affected products:** 3 ## What is CVE-2023-20867? In plain terms An attacker has to be already on the device with an administrator account, and nobody has to click anything. If it works, the attacker can read some data and change some data. ### The official description A fully compromised ESXi host can force VMware Tools to fail to authenticate host-to-guest operations, impacting the confidentiality and integrity of the guest virtual machine. ### What kind of flaw is it? - CWE-287: Improper Authentication ### How an attack on it works - Where an attacker can be: Already on the device - How hard it is to pull off: Hard: conditions must line up - Login needed first: An administrator account - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can read some data and change some data Severity vector: `CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N` ## Is CVE-2023-20867 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 14%. Exploit likelihood over the last 7 days: 14%, 14%, 14%, 14%, 14%, 14%, 14%. ### Timeline - 13 June 2023: Published - 28 October 2025: Record last updated - 16 June 2026: Exploit likelihood jumped ### How Precursor Intelligence ranks it CVE-2023-20867 scores **74 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-2023-20867? The published record lists 3 products. Versions are as published: "10.3.0 to before 12.2.5" means from 10.3.0 up to, but not including, 12.2.5. - [Tools](https://www.precursorintelligence.com/product/vmware/tools) by [VMware](https://www.precursorintelligence.com/vendors/vmware) (Application): 10.3.0 to before 12.2.5 - [Debian Linux](https://www.precursorintelligence.com/product/debian/debian_linux) by [Debian](https://www.precursorintelligence.com/vendors/debian) (Operating system): 10.0, 11.0, 12.0 - [Fedora](https://www.precursorintelligence.com/product/fedoraproject/fedora) by [Fedoraproject](https://www.precursorintelligence.com/vendors/fedoraproject) (Operating system): 37, 38, 39 ## How do I fix CVE-2023-20867? 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 - [openwall.com](http://www.openwall.com/lists/oss-security/2023/10/16/11) (Mailing list, Patch) - [openwall.com](http://www.openwall.com/lists/oss-security/2023/10/16/2) (Mailing list, Patch) - [vmware.com](https://www.vmware.com/security/advisories/VMSA-2023-0013.html) (Patch, Vendor advisory) - [lists.debian.org](https://lists.debian.org/debian-lts-announce/2023/08/msg00020.html) (Mailing list, Third-party advisory) - [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NVKQ6Y2JFJRWPFOZUOTFO3H27BK5GGOG/) (Mailing list, Release notes) - [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TJNJMD67QIT6LXLKWSHFM47DCLRSMT6W/) (Mailing list, Release notes) - [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZJM6HDRQYS74JA7YNKQBFH2XSZ52HEWH/) (Mailing list, Release notes) - [security.netapp.com](https://security.netapp.com/advisory/ntap-20230725-0001/) (Third-party advisory) - [debian.org](https://www.debian.org/security/2023/dsa-5493) (Mailing list, Third-party advisory) - [cisa.gov](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-20867) (Government resource) ## Questions ### What is CVE-2023-20867? CVE-2023-20867 is a low-severity flaw in Tools from VMware, published on 13 June 2023. An attacker has to be already on the device with an administrator account, and nobody has to click anything. If it works, the attacker can read some data and change some data. ### How serious is CVE-2023-20867? It scores 3.9 out of 10 on the CVSS severity scale, which is low. Our risk score for CVE-2023-20867 is 74 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-2023-20867 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 14%. ### Which versions does CVE-2023-20867 affect? For Tools from VMware: 10.3.0 to before 12.2.5. The record lists 3 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2023-20867? 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-2023-20867 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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