# What is CVE-2023-20168? > CVE-2023-20168 is a medium-severity flaw (CVSS 6.5) in NX-OS from Cisco, published on 23 August 2023. 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 0.2%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2023-20168 ## 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:** 45 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** Medium (CVSS 6.5 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:** 0.2% (latest exploit-likelihood forecast) - **Published:** 23 August 2023 - **Record last updated:** 25 January 2024 - **Main product:** NX-OS from Cisco - **Affected products:** 84 ## What is CVE-2023-20168? 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 take it offline. ### The official description A vulnerability in TACACS+ and RADIUS remote authentication for Cisco NX-OS Software could allow an unauthenticated, local attacker to cause an affected device to unexpectedly reload. This vulnerability is due to incorrect input validation when processing an authentication attempt if the directed request option is enabled for TACACS+ or RADIUS. An attacker could exploit this vulnerability by entering a crafted string at the login prompt of an affected device. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. ### What kind of flaw is it? - CWE-20: Improper Input Validation - CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') ### 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 take it offline Severity vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H` ## Is CVE-2023-20168 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 0.2%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 0.2%, 0.2%, 0.2%, 0.2%, 0.2%, 0.2%, 0.2%. ### Timeline - 23 August 2023: Published - 25 January 2024: Record last updated ### How Precursor Intelligence ranks it CVE-2023-20168 scores **45 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-2023-20168? The published record lists 84 products. - [NX-OS](https://www.precursorintelligence.com/product/cisco/nx-os) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 9.3(11), 10.2(5) - [Mds 9000](https://www.precursorintelligence.com/product/cisco/mds_9000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9100](https://www.precursorintelligence.com/product/cisco/mds_9100) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9132t](https://www.precursorintelligence.com/product/cisco/mds_9132t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9134](https://www.precursorintelligence.com/product/cisco/mds_9134) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9140](https://www.precursorintelligence.com/product/cisco/mds_9140) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9148](https://www.precursorintelligence.com/product/cisco/mds_9148) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9148s](https://www.precursorintelligence.com/product/cisco/mds_9148s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9148t](https://www.precursorintelligence.com/product/cisco/mds_9148t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9200](https://www.precursorintelligence.com/product/cisco/mds_9200) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9216](https://www.precursorintelligence.com/product/cisco/mds_9216) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9216a](https://www.precursorintelligence.com/product/cisco/mds_9216a) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9216i](https://www.precursorintelligence.com/product/cisco/mds_9216i) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9222i](https://www.precursorintelligence.com/product/cisco/mds_9222i) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9250i](https://www.precursorintelligence.com/product/cisco/mds_9250i) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9396s](https://www.precursorintelligence.com/product/cisco/mds_9396s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9396t](https://www.precursorintelligence.com/product/cisco/mds_9396t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9500](https://www.precursorintelligence.com/product/cisco/mds_9500) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9506](https://www.precursorintelligence.com/product/cisco/mds_9506) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9509](https://www.precursorintelligence.com/product/cisco/mds_9509) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9513](https://www.precursorintelligence.com/product/cisco/mds_9513) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9700](https://www.precursorintelligence.com/product/cisco/mds_9700) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9706](https://www.precursorintelligence.com/product/cisco/mds_9706) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9710](https://www.precursorintelligence.com/product/cisco/mds_9710) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Mds 9718](https://www.precursorintelligence.com/product/cisco/mds_9718) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 1000 Virtual Edge](https://www.precursorintelligence.com/product/cisco/nexus_1000_virtual_edge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 1000v](https://www.precursorintelligence.com/product/cisco/nexus_1000v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3048](https://www.precursorintelligence.com/product/cisco/nexus_3048) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 31108pc-V](https://www.precursorintelligence.com/product/cisco/nexus_31108pc-v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 31108tc-V](https://www.precursorintelligence.com/product/cisco/nexus_31108tc-v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 31128pq](https://www.precursorintelligence.com/product/cisco/nexus_31128pq) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3132c-Z](https://www.precursorintelligence.com/product/cisco/nexus_3132c-z) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3132q-V](https://www.precursorintelligence.com/product/cisco/nexus_3132q-v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3132q-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3132q-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3164q](https://www.precursorintelligence.com/product/cisco/nexus_3164q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3172pq](https://www.precursorintelligence.com/product/cisco/nexus_3172pq) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3172pq-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3172pq-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3172tq](https://www.precursorintelligence.com/product/cisco/nexus_3172tq) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3172tq-32t](https://www.precursorintelligence.com/product/cisco/nexus_3172tq-32t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3172tq-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3172tq-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3232](https://www.precursorintelligence.com/product/cisco/nexus_3232) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3264c-E](https://www.precursorintelligence.com/product/cisco/nexus_3264c-e) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3264q](https://www.precursorintelligence.com/product/cisco/nexus_3264q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3408-S](https://www.precursorintelligence.com/product/cisco/nexus_3408-s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 34180yc](https://www.precursorintelligence.com/product/cisco/nexus_34180yc) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 34200yc-Sm](https://www.precursorintelligence.com/product/cisco/nexus_34200yc-sm) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3432d-S](https://www.precursorintelligence.com/product/cisco/nexus_3432d-s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3464c](https://www.precursorintelligence.com/product/cisco/nexus_3464c) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3524](https://www.precursorintelligence.com/product/cisco/nexus_3524) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3524-X](https://www.precursorintelligence.com/product/cisco/nexus_3524-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3524-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3524-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3548](https://www.precursorintelligence.com/product/cisco/nexus_3548) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3548-X](https://www.precursorintelligence.com/product/cisco/nexus_3548-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3548-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3548-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 36180yc-R](https://www.precursorintelligence.com/product/cisco/nexus_36180yc-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5500](https://www.precursorintelligence.com/product/cisco/nexus_5500) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5548p](https://www.precursorintelligence.com/product/cisco/nexus_5548p) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5548up](https://www.precursorintelligence.com/product/cisco/nexus_5548up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5596t](https://www.precursorintelligence.com/product/cisco/nexus_5596t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5596up](https://www.precursorintelligence.com/product/cisco/nexus_5596up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5600](https://www.precursorintelligence.com/product/cisco/nexus_5600) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 56128p](https://www.precursorintelligence.com/product/cisco/nexus_56128p) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5624q](https://www.precursorintelligence.com/product/cisco/nexus_5624q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5648q](https://www.precursorintelligence.com/product/cisco/nexus_5648q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5672up](https://www.precursorintelligence.com/product/cisco/nexus_5672up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5672up-16g](https://www.precursorintelligence.com/product/cisco/nexus_5672up-16g) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5696q](https://www.precursorintelligence.com/product/cisco/nexus_5696q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 6000](https://www.precursorintelligence.com/product/cisco/nexus_6000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 6001](https://www.precursorintelligence.com/product/cisco/nexus_6001) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 6001p](https://www.precursorintelligence.com/product/cisco/nexus_6001p) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 6001t](https://www.precursorintelligence.com/product/cisco/nexus_6001t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 6004](https://www.precursorintelligence.com/product/cisco/nexus_6004) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 6004x](https://www.precursorintelligence.com/product/cisco/nexus_6004x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 7000](https://www.precursorintelligence.com/product/cisco/nexus_7000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 7004](https://www.precursorintelligence.com/product/cisco/nexus_7004) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 7009](https://www.precursorintelligence.com/product/cisco/nexus_7009) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 7010](https://www.precursorintelligence.com/product/cisco/nexus_7010) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 7018](https://www.precursorintelligence.com/product/cisco/nexus_7018) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9232e](https://www.precursorintelligence.com/product/cisco/nexus_9232e) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 92348gc-X](https://www.precursorintelligence.com/product/cisco/nexus_92348gc-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9408](https://www.precursorintelligence.com/product/cisco/nexus_9408) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9504](https://www.precursorintelligence.com/product/cisco/nexus_9504) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9508](https://www.precursorintelligence.com/product/cisco/nexus_9508) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9516](https://www.precursorintelligence.com/product/cisco/nexus_9516) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified ## How do I fix CVE-2023-20168? 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 - [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-remoteauth-dos-XB6pv74m) (Vendor advisory) ## Questions ### What is CVE-2023-20168? CVE-2023-20168 is a medium-severity flaw in NX-OS from Cisco, published on 23 August 2023. 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 take it offline. ### How serious is CVE-2023-20168? It scores 6.5 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2023-20168 is 45 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-2023-20168 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 0.2%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2023-20168 affect? For NX-OS from Cisco: 9.3(11), 10.2(5). The record lists 84 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2023-20168? 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-2023-20168 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