# CVE-2025-20335: Missing authorization in Cisco Session Initiation Protocol (SIP) Software > Unauthenticated remote attackers can write arbitrary files to Cisco IP phones if Web Access is enabled, potentially compromising device integrity. - **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 3 Sep 2025 - **Updated:** 3 Sep 2025 - **Also known as:** GHSA-8v48-phm3-pw95 ## What is CVE-2025-20335? CVE-2025-20335 is a medium-severity missing authorization vulnerability in Cisco Session Initiation Protocol (SIP) Software, published on 3 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability in the directory permissions of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 could allow an unauthenticated, remote attacker to write arbitrary files on an affected device. This vulnerability is due to a lack of proper authentication controls. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to perform arbitrary file writes to specific directories in the underlying operating system. Note: To exploit this vulnerability, Web Access must be enabled on the phone. Web Access is disabled by default. Weakness: CWE-284 (Improper Access Control) ## Which versions are affected by CVE-2025-20335? It affects 17 products. Products: Cisco Desk Phone 9841 Firmware, Cisco Desk Phone 9851 Firmware, Cisco Desk Phone 9861 Firmware, Cisco Desk Phone 9871 Firmware, Cisco Ip Phone 7811 Firmware, Cisco Ip Phone 7821 Firmware, Cisco Ip Phone 7841 Firmware, Cisco Ip Phone 7861 Firmware, Cisco Ip Phone 8811 Firmware, Cisco Ip Phone 8821 Firmware, Cisco Ip Phone 8841 Firmware, Cisco Ip Phone 8845 Firmware, Cisco Ip Phone 8851 Firmware, Cisco Ip Phone 8851nr Firmware, Cisco Ip Phone 8861 Firmware, Cisco Ip Phone 8865 Firmware, Cisco Video Phone 8875 Firmware. ## How do I fix CVE-2025-20335? No fix has been published for CVE-2025-20335 yet. Limit exposure of the affected software until one is available. ## Is CVE-2025-20335 being exploited? There is no known exploitation of CVE-2025-20335 in the wild and no public exploit code. ## Other vulnerabilities in Cisco Session Initiation Protocol (SIP) Software - [CVE-2025-20350](https://insights.sbomify.com/CVE-2025-20350/): Memory corruption in Cisco Session Initiation Protocol (SIP) Software (high 7.5) - [CVE-2025-20351](https://insights.sbomify.com/CVE-2025-20351/): Cross-site scripting in Cisco Session Initiation Protocol (SIP) Software (medium 6.1) - [CVE-2025-20336](https://insights.sbomify.com/CVE-2025-20336/): Information disclosure in Cisco Session Initiation Protocol (SIP) Software (medium 5.3) - [CVE-2024-20445](https://insights.sbomify.com/CVE-2024-20445/): Cisco IP Phone 7800, 8800, and 9800 Series Information Disclosure Vulnerability (medium 5.3) - [CVE-2025-20158](https://insights.sbomify.com/CVE-2025-20158/): Cisco Video Phone 8875 and Desk Phone 9800 Series Information Disclosure Vulnerability (medium 4.4) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-20335 and fix it if it is affected. What it is: CVE-2025-20335 is a medium-severity missing authorization vulnerability in Cisco Session Initiation Protocol (SIP) Software, published on 3 Sep 2025. 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-2025-20335 in the wild and no public exploit code. Affected product: Cisco Session Initiation Protocol (SIP) 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-2025-20335/ (Markdown: https://insights.sbomify.com/CVE-2025-20335/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-20335 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-20335 - OSV: https://osv.dev/vulnerability/CVE-2025-20335 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-20335/ Summaries are generated and may contain mistakes; the official description above is the record.