CVE-2020-3161 [Exploited] | Cisco Ip Phone 8865 Firmware Input Validation Bypass

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.

EDB-ID	Source	Kind	Published	Link
48342	exploit_db	edb	2020-04-17	Exploit-DB ↗
—	nvd_ref	exploit_tag		Exploit-DB ↗

EDB-ID

Source

Kind

Published

Link

48342

exploit_db

edb

2020-04-17

Exploit-DB ↗

—

nvd_ref

exploit_tag

Exploit-DB ↗

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	87.09%	83.73%	-3.36%
2	2026-04-15	77.33%	87.09%	+9.77%
3	2026-03-17	—	77.33%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

87.09%

83.73%

-3.36%

2026-04-15

77.33%

87.09%

+9.77%

2026-03-17

—

77.33%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
9.8	3.0	CRITICAL	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
10.0	2.0	HIGH	`AV:N/AC:L/Au:N/C:C/I:C/A:C` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:C) Complete confidentiality impact. Integrity impact (I:C) Complete integrity impact. Availability impact (A:C) Complete availability impact.	10.0	10.0	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

9.8

3.0

CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

10.0

2.0

HIGH

AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:C): Complete confidentiality impact.
Integrity impact (I:C): Complete integrity impact.
Availability impact (A:C): Complete availability impact.

10.0

[email protected]

Affected software / configurations for CVE-2020-3161

Vendor	Product	Version	Raw CPE
cisco	ip_phone_8865_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8865_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8865_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8865_firmware:11.0\(1\):::::::*
cisco	ip_phone_8865_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8865_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_8851_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8851_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8851_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8851_firmware:11.0\(1\):::::::*
cisco	ip_phone_8851_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8851_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_7841_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_7841_firmware:11.0\(1\):::::::*
cisco	ip_phone_7821_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_7821_firmware:11.0\(1\):::::::*
cisco	ip_phone_8811_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8811_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8811_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8811_firmware:11.0\(1\):::::::*
cisco	ip_phone_8811_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8811_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_8861_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8861_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8861_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8861_firmware:11.0\(1\):::::::*
cisco	ip_phone_8861_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8861_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_8845_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8845_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8845_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8845_firmware:11.0\(1\):::::::*
cisco	ip_phone_8845_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8845_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_7861_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_7861_firmware:11.0\(1\):::::::*
cisco	ip_phone_8841_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8841_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8841_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8841_firmware:11.0\(1\):::::::*
cisco	ip_phone_8841_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8841_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_7811_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_7811_firmware:11.0\(1\):::::::*
cisco	ip_phone_8821_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8821_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8821_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(1\):::::::*
cisco	ip_phone_8821_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(5\)sr1:::::::*
cisco	ip_phone_8821-ex_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:ip_phone_8821-ex_firmware:10.3\(1\)es14:::::::*
cisco	ip_phone_8821-ex_firmware	11.0\(1\)	cpe:2.3:o:cisco:ip_phone_8821-ex_firmware:11.0\(1\):::::::*
cisco	ip_phone_8821-ex_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:ip_phone_8821-ex_firmware:11.0\(5\)sr1:::::::*
cisco	8831_firmware	10.3\(1\)es14	cpe:2.3:o:cisco:8831_firmware:10.3\(1\)es14:::::::*
cisco	8831_firmware	11.0\(1\)	cpe:2.3:o:cisco:8831_firmware:11.0\(1\):::::::*
cisco	8831_firmware	11.0\(5\)sr1	cpe:2.3:o:cisco:8831_firmware:11.0\(5\)sr1:::::::*

References for CVE-2020-3161

URL	Tags
http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.html	Exploit Third Party Advisory VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXs	Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3161	US Government Resource

URL

CVE-2020-3161 | Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability

CISA KEV Record for CVE-2020-3161

Public exploit references (Exploit-DB) for CVE-2020-3161

Exploit prediction scoring system (EPSS) score for CVE-2020-3161

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3161

Weakness enumeration for CVE-2020-3161

Affected software / configurations for CVE-2020-3161

References for CVE-2020-3161