CVE-2020-3161

Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability

CRITICAL
9.8
CVSS Score
Published: April 15, 2020 at 08:10 PM UTC
Updated: June 17, 2026 at 03:17 AM UTC
27 products affected across 1 vendorIP Phone 8861 FirmwareIP Phone 8865 FirmwareIP Phone 8811 Firmware

Using Cisco IP phone by Cisco?

Get instant alerts when new vulnerabilities affect Cisco IP phone - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
CRITICAL9.8
Exploitation
CISA KEV
Exploit prediction
EPSS 84%
SSVC
Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score83.9%

EPSS (Exploit Prediction Scoring System) estimates a 83.9% chance this CVE is exploited in the wild within the next 30 days — higher than 100% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

Cisco IP Phones contain an improper input validation vulnerability for HTTP requests. Exploitation could allow an attacker to execute code remotely with root privileges or cause a denial-of-service (DoS) condition.

Required Action
Apply updates per vendor instructions.
Ransomware Use
Unknown
Added to KEV
Nov 3, 2021
Remediation Due
May 3, 2022
1637 days overdue

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

cisco-ip-phone-7811 (same device)
cisco-ip-phone-7821 (same device)
cisco-ip-phone-7841 (same device)
cisco-ip-phone-7861 (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCActiveAutomatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card