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.
Conclusion & alert: CVE-2025-20335 is rated Low Risk (30.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.34%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.04% | 0.34% | +0.29% |
| 2 | 2026-04-09 | 0.06% | 0.04% | -0.01% |
| 3 | 2026-02-11 | — | 0.06% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | desk_phone_9841_firmware | >= 3.0\(1\), < 3.3\(1\) | cpe:2.3:o:cisco:desk_phone_9841_firmware:*:*:*:*:*:*:*:* |
| cisco | desk_phone_9851_firmware | >= 3.0\(1\), < 3.3\(1\) | cpe:2.3:o:cisco:desk_phone_9851_firmware:*:*:*:*:*:*:*:* |
| cisco | desk_phone_9861_firmware | >= 3.0\(1\), < 3.3\(1\) | cpe:2.3:o:cisco:desk_phone_9861_firmware:*:*:*:*:*:*:*:* |
| cisco | desk_phone_9871_firmware | >= 3.0\(1\), < 3.3\(1\) | cpe:2.3:o:cisco:desk_phone_9871_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7811_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7811_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7811_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7821_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7821_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7821_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7841_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7841_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7841_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7861_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7861_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_7861_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8811_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8811_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8811_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8841_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8841_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8841_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8845_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8845_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8845_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8851_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8851_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8851_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8851nr_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8851nr_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8851nr_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8851nr_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8851nr_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8851nr_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8861_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8861_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8861_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | < 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8865_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8865_firmware:14.3\(1\):-:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | 14.3\(1\) | cpe:2.3:o:cisco:ip_phone_8865_firmware:14.3\(1\):sr1:*:*:*:*:*:* |
| cisco | video_phone_8875_firmware | < 2.3\(1\) | cpe:2.3:o:cisco:video_phone_8875_firmware:*:*:*:*:*:*:*:* |
| cisco | video_phone_8875_firmware | >= 3.0\(1\), < 3.3\(1\) | cpe:2.3:o:cisco:video_phone_8875_firmware:*:*:*:*:*:*:*:* |
| cisco | video_phone_8875_firmware | 2.3\(1\) | cpe:2.3:o:cisco:video_phone_8875_firmware:2.3\(1\):-:*:*:*:*:*:* |
| cisco | video_phone_8875_firmware | 2.3\(1\) | cpe:2.3:o:cisco:video_phone_8875_firmware:2.3\(1\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | < 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:*:*:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):-:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr1:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr2:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr4:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr5:*:*:*:*:*:* |
| cisco | ip_phone_8821_firmware | 11.0\(6\) | cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr6:*:*:*:*:*:* |