CVE-2020-3111 | Cisco IP Phone Remote Code Execution and Denial of Service Vulnerability

A vulnerability in the Cisco Discovery Protocol implementation for the Cisco IP Phone could allow an unauthenticated, adjacent attacker to remotely execute code with root privileges or cause a reload of an affected IP phone. The vulnerability is due to missing checks when processing Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to the targeted IP phone. 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 denial of service (DoS) condition. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

Published: 2020-02-05 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-3111 is rated High Risk (68.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.09%). Core evidence: EPSS rose +2.93% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-3111

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.17% 3.09% +2.93%
2 2025-03-30 0.60% 0.17% -0.43%
3 2025-03-29 0.60%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3111

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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.
2.8 5.9 [email protected]
8.8 3.0 HIGH
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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.
2.8 5.9 [email protected]
8.3 2.0 HIGH
AV:A/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:A)
Requires access to an adjacent network segment.
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.
6.5 10.0 [email protected]

Weakness enumeration for CVE-2020-3111

Affected software / configurations for CVE-2020-3111

Vendor Product Version Raw CPE
cisco ip_conference_phone_7832_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:*:*:*:*:*:*:*:*
cisco ip_conference_phone_7832_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_conference_phone_7832_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_conference_phone_8832_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:*:*:*:*:*:*:*:*
cisco ip_conference_phone_8832_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_conference_phone_8832_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_6821_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_6821_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_6841_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_6841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_6851_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_6851_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_6861_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_6861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_6871_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_6871_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7811_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_7811_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7811_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_7811_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7821_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_7821_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7821_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_7821_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7841_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_7841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7841_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_7841_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7861_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_7861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7861_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_7861_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8811_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_8811_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8811_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_8811_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8841_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_8841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8841_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_8841_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8851_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_8851_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8851_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_8851_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8861_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_8861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8861_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_8861_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8845_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_8845_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8845_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_8845_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8865_firmware < 12.7\(1\) cpe:2.3:o:cisco:ip_phone_8865_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8865_with_multiplatform_firmware < 11.3\(1\)sr1 cpe:2.3:o:cisco:ip_phone_8865_with_multiplatform_firmware:*:*:*:*:*:*:*:*
cisco unified_ip_conference_phone_8831_firmware < 10.3\(1\)sr6 cpe:2.3:o:cisco:unified_ip_conference_phone_8831_firmware:*:*:*:*:*:*:*:*
cisco unified_ip_conference_phone_8831_for_third-party_call_control_firmware cpe:2.3:o:cisco:unified_ip_conference_phone_8831_for_third-party_call_control_firmware:-:*:*:*:*:*:*:*
cisco wireless_ip_phone_8821_firmware < 11.0\(5\)sr2 cpe:2.3:o:cisco:wireless_ip_phone_8821_firmware:*:*:*:*:*:*:*:*
cisco wireless_ip_phone_8821-ex_firmware < 11.0\(5\)sr2 cpe:2.3:o:cisco:wireless_ip_phone_8821-ex_firmware:*:*:*:*:*:*:*:*

References for CVE-2020-3111

cvelogic Threat Intelligence