CVE-2020-3161 Cisco Cisco IP Phones: command or code injection
In plain words: The program treats text it receives as instructions instead of plain data. The attacker can run commands on the machine — often the whole device is taken over.
Confirmed exploited by CISA on · US federal patch deadline May 3, 2022
What to do
- Install Cisco's security update for Cisco IP Phones. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Patch edge devices first — attackers often start scanning for them within hours of a fix.
- Never expose the device's admin page to the internet.
- After patching a device that was exposed, follow the vendor's compromise checks, end active sessions and change passwords.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: They face the internet and guard the whole network, so a flaw here can hand attackers a way in — and these devices usually run no antivirus, so break-ins go unnoticed.
The details
- Official name
- Cisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability
- Product
- Cisco Cisco IP Phones
- CISA 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.
- Type of flaw
- Command or code injection (CWE-20)
- Confirmed exploited
- Nov 3, 2021
- US federal patch deadline
- May 3, 2022
Ask Cleus about it
Ask about a vulnerability, an update, a weird message, or the news. Plain-word answers, free, no account.
Answering about CVE-2020-3161 ·
Questions about CVE-2020-3161
Is CVE-2020-3161 being exploited?
Yes. CISA added CVE-2020-3161 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2020-3161?
Install Cisco's security update for Cisco IP Phones. If no update exists, follow the vendor's workaround or stop using the product until one ships. Patch edge devices first — attackers often start scanning for them within hours of a fix.
Am I affected by CVE-2020-3161?
Only if you use Cisco Cisco IP Phones. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.