# What is CVE-2018-0303? > CVE-2018-0303 is a high-severity flaw (CVSS 8.8) in NX-OS from Cisco, published on 21 June 2018. 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 1.1%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2018-0303 ## 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:** 48 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** High (CVSS 8.8 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:** 1.1% (latest exploit-likelihood forecast) - **Published:** 21 June 2018 - **Record last updated:** 20 April 2023 - **Main product:** NX-OS from Cisco - **Affected products:** 84 ## What is CVE-2018-0303? In plain terms An attacker has to be on the same local network 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 Cisco Discovery Protocol component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code as root or cause a denial of service (DoS) condition on the affected device. The vulnerability exists because of insufficiently validated Cisco Discovery Protocol packet headers. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to a Layer 2 adjacent affected device. A successful exploit could allow the attacker to cause a buffer overflow that could allow the attacker to execute arbitrary code as root or cause a DoS condition on the affected device. This vulnerability affects the following if configured to use Cisco Discovery Protocol: Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 1000V Series Switches, Nexus 1100 Series Cloud Services Platforms, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvc22202, CSCvc22205, CSCvc22208, CSCvc88078, CSCvc88150, CSCvc88159, CSCvc88162, CSCvc88167. ### What kind of flaw is it? - CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer - CWE-20: Improper Input Validation ### How an attack on it works - Where an attacker can be: On the same local network - 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:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` ## Is CVE-2018-0303 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 1.1%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 1.1%, 1.1%, 1.1%, 1.1%, 1.1%, 1.1%, 1.1%. ### Timeline - 21 June 2018: Published - 20 April 2023: Record last updated ### How Precursor Intelligence ranks it CVE-2018-0303 scores **48 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-2018-0303? The published record lists 84 products. Versions are as published: "1.1 to before 1.1.4.179" means from 1.1 up to, but not including, 1.1.4.179. - [NX-OS](https://www.precursorintelligence.com/product/cisco/nx-os) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 3.1(3a)a, 7.0(0)hsk(0.357), 7.0(3)i4(7), 7.0(3)i7(1), 8.0(1), 8.1(0.2)s0, 8.8(0.1), 8.8(3.5)s0 - [Firepower Extensible Operating System](https://www.precursorintelligence.com/product/cisco/firepower_extensible_operating_system) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 1.1 to before 1.1.4.179, 2.0 to before 2.0.1.153, 2.1.1 to before 2.1.1.86, 2.2.1 to before 2.2.1.70, 2.2.2 to before 2.2.2.17 - [Firepower 4110](https://www.precursorintelligence.com/product/cisco/firepower_4110) 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 4140](https://www.precursorintelligence.com/product/cisco/firepower_4140) 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 Security Appliance](https://www.precursorintelligence.com/product/cisco/firepower_9300_security_appliance) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 172tq-Xl](https://www.precursorintelligence.com/product/cisco/nexus_172tq-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2148t](https://www.precursorintelligence.com/product/cisco/nexus_2148t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2224tp Ge](https://www.precursorintelligence.com/product/cisco/nexus_2224tp_ge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2232pp 10ge](https://www.precursorintelligence.com/product/cisco/nexus_2232pp_10ge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2232tm 10ge](https://www.precursorintelligence.com/product/cisco/nexus_2232tm_10ge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2232tm-E 10ge](https://www.precursorintelligence.com/product/cisco/nexus_2232tm-e_10ge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2248pq 10ge](https://www.precursorintelligence.com/product/cisco/nexus_2248pq_10ge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2248tp Ge](https://www.precursorintelligence.com/product/cisco/nexus_2248tp_ge) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 2248tp-E](https://www.precursorintelligence.com/product/cisco/nexus_2248tp-e) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3016](https://www.precursorintelligence.com/product/cisco/nexus_3016) 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 3064-32t](https://www.precursorintelligence.com/product/cisco/nexus_3064-32t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3064-T](https://www.precursorintelligence.com/product/cisco/nexus_3064-t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3064-X](https://www.precursorintelligence.com/product/cisco/nexus_3064-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3100-V](https://www.precursorintelligence.com/product/cisco/nexus_3100-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](https://www.precursorintelligence.com/product/cisco/nexus_3132q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 3132q-X](https://www.precursorintelligence.com/product/cisco/nexus_3132q-x) 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 3232c](https://www.precursorintelligence.com/product/cisco/nexus_3232c) 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 34180yc](https://www.precursorintelligence.com/product/cisco/nexus_34180yc) 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 3636c-R](https://www.precursorintelligence.com/product/cisco/nexus_3636c-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5000](https://www.precursorintelligence.com/product/cisco/nexus_5000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5010](https://www.precursorintelligence.com/product/cisco/nexus_5010) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 5020](https://www.precursorintelligence.com/product/cisco/nexus_5020) 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 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 5696q](https://www.precursorintelligence.com/product/cisco/nexus_5696q) 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 7000](https://www.precursorintelligence.com/product/cisco/nexus_7000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 7700](https://www.precursorintelligence.com/product/cisco/nexus_7700) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 92160yc-X](https://www.precursorintelligence.com/product/cisco/nexus_92160yc-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 92304qc](https://www.precursorintelligence.com/product/cisco/nexus_92304qc) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9236c](https://www.precursorintelligence.com/product/cisco/nexus_9236c) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9272q](https://www.precursorintelligence.com/product/cisco/nexus_9272q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 93108tc-EX](https://www.precursorintelligence.com/product/cisco/nexus_93108tc-ex) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 93120tx](https://www.precursorintelligence.com/product/cisco/nexus_93120tx) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 93128tx](https://www.precursorintelligence.com/product/cisco/nexus_93128tx) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 93180yc-EX](https://www.precursorintelligence.com/product/cisco/nexus_93180yc-ex) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9332pq](https://www.precursorintelligence.com/product/cisco/nexus_9332pq) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9372px](https://www.precursorintelligence.com/product/cisco/nexus_9372px) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9372tx](https://www.precursorintelligence.com/product/cisco/nexus_9372tx) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9396px](https://www.precursorintelligence.com/product/cisco/nexus_9396px) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus 9396tx](https://www.precursorintelligence.com/product/cisco/nexus_9396tx) 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 - [Nexus C36180yc-R](https://www.precursorintelligence.com/product/cisco/nexus_c36180yc-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus N9k-C9508-Fm-R](https://www.precursorintelligence.com/product/cisco/nexus_n9k-c9508-fm-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus N9k-X9636c-R](https://www.precursorintelligence.com/product/cisco/nexus_n9k-x9636c-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [Nexus N9k-X9636q-R](https://www.precursorintelligence.com/product/cisco/nexus_n9k-x9636q-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [UCS 6120xp](https://www.precursorintelligence.com/product/cisco/ucs_6120xp) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [UCS 6140xp](https://www.precursorintelligence.com/product/cisco/ucs_6140xp) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [UCS 6248up](https://www.precursorintelligence.com/product/cisco/ucs_6248up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [UCS 6296up](https://www.precursorintelligence.com/product/cisco/ucs_6296up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [UCS 6324](https://www.precursorintelligence.com/product/cisco/ucs_6324) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified - [UCS 6332](https://www.precursorintelligence.com/product/cisco/ucs_6332) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified ## How do I fix CVE-2018-0303? 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-20180620-fxnxos-dos) (Vendor advisory) - [securitytracker.com](http://www.securitytracker.com/id/1041169) (Third-party advisory, Vulnerability database) ## Questions ### What is CVE-2018-0303? CVE-2018-0303 is a high-severity flaw in NX-OS from Cisco, published on 21 June 2018. An attacker has to be on the same local network 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-2018-0303? It scores 8.8 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2018-0303 is 48 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-2018-0303 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 1.1%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2018-0303 affect? For NX-OS from Cisco: 3.1(3a)a, 7.0(0)hsk(0.357), 7.0(3)i4(7), 7.0(3)i7(1), 8.0(1), 8.1(0.2)s0 and 2 more. The record lists 84 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2018-0303? 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-2018-0303 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