CVE-2020-3161
Published: November 3, 2021
Official Description
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.
CISA KEV Advisory
Cisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability
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.
Apply updates per vendor instructions.
Risk Analysis
Cisco IP Phones are vulnerable to improper input validation in HTTP requests, which could allow an attacker to remotely execute code with root privileges or cause a denial-of-service. The high EPSS score of 0.83148 suggests a high likelihood of exploitation. This vulnerability is confirmed to be actively exploited, as it is in CISA's KEV.
This vulnerability is actively being exploited in the wild. The flaw is remotely exploitable, allowing attackers to target affected Cisco IP Phones over the network.
Update Cisco IP Phones to the latest firmware versions to address the input validation vulnerability. Implement network segmentation to restrict access to these devices.
Technical Analysis
CVE-2020-3161 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2020-3161 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-3161 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1