CVE-2020-3161
A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause…
Browse: All 2020 CVEs · All vendors
- CVSS score
- 9.8 Critical
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CISA KEV
- Yes — actively exploited (added 2021-11-03, remediation due 2022-05-03)
- Weakness (CWE)
- CWE-20
- Published
- 2020-04-15
- Last modified
- 2026-06-17
- NVD status
- Analyzed
Description
A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause a reload of an affected IP phone, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web server of a targeted device. A successful exploit could allow the attacker to remotely execute code with root privileges or cause a reload of an affected IP phone, resulting in a DoS condition.
Affected products
- cisco ip phone 8865 firmware
- cisco ip phone 8851 firmware
- cisco ip phone 7841 firmware
- cisco ip phone 7821 firmware
- cisco ip phone 8811 firmware
- cisco ip phone 8861 firmware
- cisco ip phone 8845 firmware
- cisco ip phone 7861 firmware
- cisco ip phone 8841 firmware
- cisco ip phone 7811 firmware
- cisco ip phone 8821 firmware
- cisco ip phone 8821-ex firmware
Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.
Required action (CISA)
Apply updates per vendor instructions. Federal remediation deadline: 2022-05-03.
How to prioritize this
This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score. For the actively exploited vulnerabilities that matter this week, read The Exploit HQ daily security brief.
References
- http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.html
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXs
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3161
FAQ
Is CVE-2020-3161 actively exploited?
Yes. CISA added CVE-2020-3161 to its Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, with a federal remediation deadline of 2022-05-03. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.
What is the CVSS score of CVE-2020-3161?
CVE-2020-3161 has a CVSS base score of 9.8 (Critical). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Related vulnerabilities
- CVE-2026-76519 — Cisco Secure Email Gateway
- CVE-2026-76504 — Cisco Catalyst SD-WAN Manager
- CVE-2026-76460 — Cisco Identity Services Engine
- CVE-2026-76461 — Cisco Secure Email Gateway
- CVE-2026-20079 — Cisco Secure Firewall Management Center (F
- CVE-2026-20349 — Cisco Secure Firewall Adaptive Security Ap
Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.
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