# CVE-2024-20294: Denial of service in Cisco Firepower Extensible Operating System (FXOS) > An adjacent attacker can cause a denial of service on Cisco FXOS and NX-OS devices by sending crafted LLDP packets, potentially crashing the service or reloading the device. - **Severity:** Medium 6.6 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** A user has to click or open something - **Fix available:** No - **Published:** 28 Feb 2024 - **Updated:** 1 Aug 2024 - **Also known as:** GHSA-jjfr-9fr6-hh6r ## What is CVE-2024-20294? CVE-2024-20294 is a medium-severity denial of service vulnerability in Cisco Firepower Extensible Operating System, published on 28 Feb 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link. ### Official description A vulnerability in the Link Layer Discovery Protocol (LLDP) feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of specific fields in an LLDP frame. An attacker could exploit this vulnerability by sending a crafted LLDP packet to an interface of an affected device and having an authenticated user retrieve LLDP statistics from the affected device through CLI show commands or Simple Network Management Protocol (SNMP) requests. A successful exploit could allow the attacker to cause the LLDP service to crash and stop running on the affected device. In certain situations, the LLDP crash may result in a reload of the affected device. Note: LLDP is a Layer 2 link protocol. To exploit this vulnerability, an attacker would need to be directly connected to an interface of an affected device, either physically or logically (for example, through a Layer 2 Tunnel configured to transport the LLDP protocol). Weakness: CWE-805 (Buffer Access with Incorrect Length Value) ## Which versions are affected by CVE-2024-20294? It affects 3 products. Products: Cisco Firepower Extensible Operating System, Cisco Nx-Os, Cisco Unified Computing System. ## How do I fix CVE-2024-20294? No fix has been published for CVE-2024-20294 yet. Limit exposure of the affected software until one is available. ## Is CVE-2024-20294 being exploited? There is no known exploitation of CVE-2024-20294 in the wild and no public exploit code. ## Other vulnerabilities in Cisco Firepower Extensible Operating System - [CVE-2018-0310](https://insights.sbomify.com/CVE-2018-0310/): Information disclosure in Cisco FXOS and NX-OS unknown (critical 9.8) - [CVE-2015-6435](https://insights.sbomify.com/CVE-2015-6435/): Command injection in n/a (critical 9.8) - [CVE-2021-1368](https://insights.sbomify.com/CVE-2021-1368/): Memory corruption in Cisco NX-OS Software (high 8.8) - [CVE-2020-3456](https://insights.sbomify.com/CVE-2020-3456/): Cisco FXOS Software Firepower Chassis Manager Cross-Site Request Forgery Vulnerability (high 8.8) - [CVE-2020-3172](https://insights.sbomify.com/CVE-2020-3172/): Cisco FXOS and NX-OS Software Cisco Discovery Protocol Arbitrary Code Execution and Denial of Service Vulnerability (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-20294 and fix it if it is affected. What it is: CVE-2024-20294 is a medium-severity denial of service vulnerability in Cisco Firepower Extensible Operating System, published on 28 Feb 2024. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2024-20294 in the wild and no public exploit code. Affected product: Cisco Firepower Extensible Operating System. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-20294/ (Markdown: https://insights.sbomify.com/CVE-2024-20294/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-20294 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-20294 - OSV: https://osv.dev/vulnerability/CVE-2024-20294 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-20294/ Summaries are generated and may contain mistakes; the official description above is the record.