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Fencer Vulns
medium 6.5

CVE-2021-1379 json

Cisco IP Phones Cisco Discovery Protocol and Link Layer Discovery Protocol Remote Code Execution and Denial of Service Vulnerabilities

published 2024-11-18 23 mo ago modified 2026-06-17 4 mo ago also EUVD-2021-6846

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

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.

Patch / fix

  • cisco ip_conference_phone_7832_firmware 12.8\(1\)
  • 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_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_with_multiplatform_firmware 11.3\(2\)
  • cisco ip_phone_7821_firmware 12.8\(1\)
  • cisco ip_phone_7821_with_multiplatform_firmware 11.3\(2\)
  • cisco ip_phone_7841_firmware 12.8\(1\)
  • cisco ip_phone_7841_with_multiplatform_firmware 11.3\(2\)
  • cisco ip_phone_7861_firmware 12.8\(1\)
  • cisco ip_phone_7861_with_multiplatform_firmware 11.3\(2\)
  • cisco ip_phone_8811_firmware 12.8\(1\)
  • cisco ip_phone_8811_with_multiplatform_firmware 11.3\(2\)
  • cisco ip_phone_8841_firmware 12.8\(1\)

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
23 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/RL:X/RC:X/E:X
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Cisco Cisco IP Phones with Multiplatform Firmware
  • Cisco Cisco Session Initiation Protocol (SIP) Software
  • Cisco Cisco Small Business IP Phones

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.