# CVE-2024-20509: Race condition in Cisco Meraki MX Firmware > An unauthenticated remote attacker can hijack AnyConnect VPN sessions or cause denial of service by exploiting weak entropy and a race condition in the authentication process. - **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 2 Oct 2024 - **Updated:** 4 Jun 2025 - **Also known as:** GHSA-frxm-f6qg-2mch ## What is CVE-2024-20509? CVE-2024-20509 is a medium-severity vulnerability in Cisco Meraki MX Firmware, published on 2 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to hijack an AnyConnect VPN session or cause a denial of service (DoS) condition for individual users of the AnyConnect VPN service on an affected device. This vulnerability is due to weak entropy for handlers that are used during the VPN authentication process as well as a race condition that exists in the same process. An attacker could exploit this vulnerability by correctly guessing an authentication handler and then sending crafted HTTPS requests to an affected device. A successful exploit could allow the attacker to take over the AnyConnect VPN session from a target user or prevent the target user from establishing an AnyConnect VPN session with the affected device. Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization) ## Which versions are affected by CVE-2024-20509? It affects 25 products. Products: Cisco Meraki Mx100 Firmware, Cisco Meraki Mx105 Firmware, Cisco Meraki Mx250 Firmware, Cisco Meraki Mx400 Firmware, Cisco Meraki Mx450 Firmware, Cisco Meraki Mx600 Firmware, Cisco Meraki Mx64 Firmware, Cisco Meraki Mx64w Firmware, Cisco Meraki Mx65 Firmware, Cisco Meraki Mx65w Firmware, Cisco Meraki Mx67 Firmware, Cisco Meraki Mx67c Firmware, Cisco Meraki Mx67w Firmware, Cisco Meraki Mx68 Firmware, Cisco Meraki Mx68cw Firmware, Cisco Meraki Mx68w Firmware, Cisco Meraki Mx75 Firmware, Cisco Meraki Mx84 Firmware, Cisco Meraki Mx85 Firmware, Cisco Meraki Mx95 Firmware and 5 more. ## How do I fix CVE-2024-20509? No fix has been published for CVE-2024-20509 yet. Limit exposure of the affected software until one is available. ## Is CVE-2024-20509 being exploited? There is no known exploitation of CVE-2024-20509 in the wild and no public exploit code. ## Other vulnerabilities in Cisco Meraki MX Firmware - [CVE-2024-20498](https://insights.sbomify.com/CVE-2024-20498/): Denial of service in Cisco Meraki MX Firmware (high 8.6) - [CVE-2024-20499](https://insights.sbomify.com/CVE-2024-20499/): Denial of service in Cisco Meraki MX Firmware (high 8.6) - [CVE-2024-20501](https://insights.sbomify.com/CVE-2024-20501/): Denial of service in Cisco Meraki MX Firmware (high 8.6) - [CVE-2022-20933](https://insights.sbomify.com/CVE-2022-20933/): Cisco Meraki MX and Z3 Teleworker Gateway VPN Denial of Service Vulnerability (high 8.6) - [CVE-2024-20500](https://insights.sbomify.com/CVE-2024-20500/): Denial of service in Cisco Meraki MX Firmware (medium 5.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-20509 and fix it if it is affected. What it is: CVE-2024-20509 is a medium-severity vulnerability in Cisco Meraki MX Firmware, published on 2 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-20509 in the wild and no public exploit code. Affected product: Cisco Meraki MX Firmware. 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-2024-20509/ (Markdown: https://insights.sbomify.com/CVE-2024-20509/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-20509 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-20509 - OSV: https://osv.dev/vulnerability/CVE-2024-20509 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-20509/ Summaries are generated and may contain mistakes; the official description above is the record.