# CVE-2024-20355: Missing authorization in Cisco Adaptive Security Appliance (ASA) Software > Authenticated attackers can bypass VPN authorization checks to access unauthorized network segments by reusing SAML tokens across tunnel groups. - **Severity:** Medium 5.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 22 May 2024 - **Updated:** 1 Aug 2024 - **Also known as:** GHSA-2fpj-x8pr-gx6p ## What is CVE-2024-20355? CVE-2024-20355 is a medium-severity missing authorization vulnerability in Cisco Adaptive Security Appliance Software, published on 22 May 2024. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description A vulnerability in the implementation of SAML 2.0 single sign-on (SSO) for remote access VPN services in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to successfully establish a VPN session on an affected device. This vulnerability is due to improper separation of authorization domains when using SAML authentication. An attacker could exploit this vulnerability by using valid credentials to successfully authenticate using their designated connection profile (tunnel group), intercepting the SAML SSO token that is sent back from the Cisco ASA device, and then submitting the same SAML SSO token to a different tunnel group for authentication. A successful exploit could allow the attacker to establish a remote access VPN session using a connection profile that they are not authorized to use and connect to secured networks behind the affected device that they are not authorized to access. For successful exploitation, the attacker must have valid remote access VPN user credentials. Weakness: CWE-862 (Missing Authorization) ## Which versions are affected by CVE-2024-20355? It affects 2 products. Products: Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense. ## How do I fix CVE-2024-20355? No fix has been published for CVE-2024-20355 yet. Limit exposure of the affected software until one is available. ## Is CVE-2024-20355 being exploited? There is no known exploitation of CVE-2024-20355 in the wild and no public exploit code. ## Other vulnerabilities in Cisco Adaptive Security Appliance Software - [CVE-2025-20333](https://insights.sbomify.com/CVE-2025-20333/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow (critical 9.9, exploited in the wild) - [CVE-2016-6366](https://insights.sbomify.com/CVE-2016-6366/): Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow (high 8.8, exploited in the wild) - [CVE-2026-20349](https://insights.sbomify.com/CVE-2026-20349/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection (high 8.6, exploited in the wild) - [CVE-2024-20353](https://insights.sbomify.com/CVE-2024-20353/): Cisco ASA and FTD Denial of Service (high 8.6, exploited in the wild) - [CVE-2016-6367](https://insights.sbomify.com/CVE-2016-6367/): Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-20355 and fix it if it is affected. What it is: CVE-2024-20355 is a medium-severity missing authorization vulnerability in Cisco Adaptive Security Appliance Software, published on 22 May 2024. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-20355 in the wild and no public exploit code. Affected product: Cisco Adaptive Security Appliance Software. 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-2024-20355/ (Markdown: https://insights.sbomify.com/CVE-2024-20355/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-20355 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-20355 - OSV: https://osv.dev/vulnerability/CVE-2024-20355 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-20355/ Summaries are generated and may contain mistakes; the official description above is the record.