Vulnerability Database

328,409

Total vulnerabilities in the database

CVE-2021-1379

Multiple vulnerabilities in the Cisco Discovery Protocol and Link Layer Discovery Protocol (LLDP) implementations for Cisco IP Phone Series 68xx/78xx/88xx could allow an unauthenticated, adjacent attacker to execute code remotely or cause a reload of an affected IP phone. These vulnerabilities are due to missing checks when the IP phone processes a Cisco Discovery Protocol or LLDP packet. An attacker could exploit these vulnerabilities by sending a malicious Cisco Discovery Protocol or LLDP packet to the targeted IP phone. A successful exploit could allow the attacker to execute code on the affected IP phone or cause it to reload unexpectedly, resulting in a denial of service (DoS) condition.Note: Cisco Discovery Protocol is a Layer 2 protocol. To exploit these vulnerabilities, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

  • Published: Nov 18, 2024
  • Updated: Nov 16, 2025
  • CVE: CVE-2021-1379
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 6.5
  • AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWEs:

Software From Fixed in
cisco / ip_conference_phone_7832_firmware - 12.8\(1\)
cisco / ip_conference_phone_7832_firmware 12.8(1) 12.8(1).x
cisco / ip_conference_phone_7832_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_conference_phone_8832_firmware - 12.8\(1\)
cisco / ip_conference_phone_8832_firmware 12.8(1) 12.8(1).x
cisco / ip_conference_phone_8832_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_6821_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_6841_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_6851_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_6861_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_6871_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_7811_firmware - 12.8\(1\)
cisco / ip_phone_7811_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_7811_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_7821_firmware - 12.8\(1\)
cisco / ip_phone_7821_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_7821_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_7841_firmware - 12.8\(1\)
cisco / ip_phone_7841_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_7841_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_7861_firmware - 12.8\(1\)
cisco / ip_phone_7861_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_7861_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_8811_firmware - 12.8\(1\)
cisco / ip_phone_8811_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_8811_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_8841_firmware - 12.8\(1\)
cisco / ip_phone_8841_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_8841_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_8851_firmware - 12.8\(1\)
cisco / ip_phone_8851_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_8851_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_8861_firmware - 12.8\(1\)
cisco / ip_phone_8861_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_8861_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_8845_firmware - 12.8\(1\)
cisco / ip_phone_8845_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_8845_with_multiplatform_firmware - 11.3\(2\)
cisco / ip_phone_8865_firmware - 12.8\(1\)
cisco / ip_phone_8865_firmware 12.8(1) 12.8(1).x
cisco / ip_phone_8865_with_multiplatform_firmware - 11.3\(2\)
cisco / unified_ip_conference_phone_8831_firmware - 10.3\(1\)
cisco / unified_ip_conference_phone_8831_firmware 10.3(1) 10.3(1).x
cisco / unified_ip_conference_phone_8831_firmware 10.3(1)-sr1 10.3(1)-sr1.x
cisco / unified_ip_conference_phone_8831_firmware 10.3(1)-sr2 10.3(1)-sr2.x
cisco / unified_ip_conference_phone_8831_firmware 10.3(1)-sr3 10.3(1)-sr3.x
cisco / unified_ip_conference_phone_8831_firmware 10.3(1)-sr4b 10.3(1)-sr4b.x
cisco / unified_ip_conference_phone_8831_firmware 10.3(1)-sr6 10.3(1)-sr6.x
cisco / wireless_ip_phone_8821_firmware - 11.0\(6.6\)
cisco / wireless_ip_phone_8821-ex_firmware - 11.0\(6.6\)

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.