Vulnerability Database

328,409

Total vulnerabilities in the database

CVE-2025-20335

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.

  • Published: Sep 3, 2025
  • Updated: Nov 16, 2025
  • CVE: CVE-2025-20335
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 5.3
  • AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Software From Fixed in
cisco / desk_phone_9841_firmware 3.0\(1\) 3.3\(1\)
cisco / desk_phone_9851_firmware 3.0\(1\) 3.3\(1\)
cisco / desk_phone_9861_firmware 3.0\(1\) 3.3\(1\)
cisco / desk_phone_9871_firmware 3.0\(1\) 3.3\(1\)
cisco / ip_phone_7811_firmware - 14.3\(1\)
cisco / ip_phone_7811_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_7811_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_7821_firmware - 14.3\(1\)
cisco / ip_phone_7821_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_7821_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_7841_firmware - 14.3\(1\)
cisco / ip_phone_7841_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_7841_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_7861_firmware - 14.3\(1\)
cisco / ip_phone_7861_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_7861_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8811_firmware - 14.3\(1\)
cisco / ip_phone_8811_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8811_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8841_firmware - 14.3\(1\)
cisco / ip_phone_8841_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8841_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8845_firmware - 14.3\(1\)
cisco / ip_phone_8845_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8845_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8851_firmware - 14.3\(1\)
cisco / ip_phone_8851_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8851_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8851nr_firmware - 14.3\(1\)
cisco / ip_phone_8851nr_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8851nr_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8861_firmware - 14.3\(1\)
cisco / ip_phone_8861_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8861_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / ip_phone_8865_firmware - 14.3\(1\)
cisco / ip_phone_8865_firmware 14.3(1) 14.3(1).x
cisco / ip_phone_8865_firmware 14.3(1)-sr1 14.3(1)-sr1.x
cisco / video_phone_8875_firmware - 2.3\(1\)
cisco / video_phone_8875_firmware 3.0\(1\) 3.3\(1\)
cisco / video_phone_8875_firmware 2.3(1) 2.3(1).x
cisco / video_phone_8875_firmware 2.3(1)-sr1 2.3(1)-sr1.x
cisco / ip_phone_8821_firmware - 11.0\(6\)
cisco / ip_phone_8821_firmware 11.0(6) 11.0(6).x
cisco / ip_phone_8821_firmware 11.0(6)-sr1 11.0(6)-sr1.x
cisco / ip_phone_8821_firmware 11.0(6)-sr2 11.0(6)-sr2.x
cisco / ip_phone_8821_firmware 11.0(6)-sr4 11.0(6)-sr4.x
cisco / ip_phone_8821_firmware 11.0(6)-sr5 11.0(6)-sr5.x
cisco / ip_phone_8821_firmware 11.0(6)-sr6 11.0(6)-sr6.x

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.