CVE-2019-1684 | Cisco IP Phone 7800 and 8800 Series Cisco Discovery Protocol and Link Layer Discovery Protocol Denial of Service Vulnerability

A vulnerability in the Cisco Discovery Protocol or Link Layer Discovery Protocol (LLDP) implementation for the Cisco IP Phone 7800 and 8800 Series could allow an unauthenticated, adjacent attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability is due to missing length validation of certain Cisco Discovery Protocol or LLDP packet header fields. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol or LLDP packet to the targeted phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition. Versions prior to 12.6(1)MN80 are affected.

Published: 2019-02-21 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2019-1684 is rated Moderate Risk (42.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.64%). Mandatory action: Review affected assets and schedule 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-2019-1684

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 0.14% 0.64% +0.50%
2 2025-03-30 0.18% 0.14% -0.03%
3 2025-03-29 0.18%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-1684

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 3.6 [email protected]
6.5 3.0 MEDIUM
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 3.6 [email protected]
6.1 2.0 MEDIUM
AV:A/AC:L/Au:N/C:N/I:N/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:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
6.5 6.9 [email protected]

Weakness enumeration for CVE-2019-1684

Affected software / configurations for CVE-2019-1684

Vendor Product Version Raw CPE
cisco ip_phone_8800_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8800_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7800_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_7800_firmware:*:*:*:*:*:*:*:*
cisco ip_conference_phone_7832_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:*:*:*:*:*:*:*:*
cisco ip_conference_phone_8832_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7811_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_7811_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7821_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_7821_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7841_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_7841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_7861_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_7861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8811_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8811_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8841_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8841_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8845_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8845_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8851_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8851_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8861_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8861_firmware:*:*:*:*:*:*:*:*
cisco ip_phone_8865_firmware < 12.6\(1\)mn80 cpe:2.3:o:cisco:ip_phone_8865_firmware:*:*:*:*:*:*:*:*

References for CVE-2019-1684

cvelogic Threat Intelligence