CVE-2020-3161
Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.8
Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability
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.
- Record
CVE-2020-3161- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2020-24432
9.8
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.
- Record
EUVD-2020-24432- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-74vv-6p4c-8fhj
9.8
A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote...
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.
- Record
GHSA-74vv-6p4c-8fhj- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
CISA KEV No score
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.
- Record
CVE-2020-3161- Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
9.8
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.
- Record
CVE-2020-3161- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 10.0 High
AV:N/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
- cisco ip phone
- cisco ip phones
- cisco 8831 firmware
- cisco ip phone 7811 firmware
- cisco ip phone 7821 firmware
- cisco ip phone 7841 firmware
- cisco ip phone 7861 firmware
- cisco ip phone 8811 firmware
- cisco ip phone 8821-ex firmware
- cisco ip phone 8821 firmware
- cisco ip phone 8841 firmware
- cisco ip phone 8845 firmware
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | Cisco IP Phone 11.7 - Denial of service (PoC) | 2020-04-17 |
| PoC in GitHub | abood05972/CVE-2020-3161 | 2020-12-31 |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation | ||
| first indexed | CVE List, EUVD, Exploit-DB, GitHub Advisories, CISA KEV, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-3161 is a critical vulnerability (CVSS 9.8) in Cisco Ip Phone, published April 15, 2020. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 83.9%, the 99th percentile. No source names a fixed version.
References
tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXs
packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.html
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3161
nvd.nist.gov/vuln/detail/CVE-2020-3161
github.com/advisories/GHSA-74vv-6p4c-8fhj