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.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipphone-rce-dos-U2PsSkz3

Affected Products

• Vulnerable Products

  At the time of publication, these vulnerabilities affected the following Cisco IP phones with Cisco Discovery Protocol or LLDP enabled and running a vulnerable firmware release:

  • IP Conference Phone 7832
  • IP Conference Phone 7832 with Multiplatform Firmware
  • IP Conference Phone 8832
  • IP Conference Phone 8832 with Multiplatform Firmware
  • IP Phone 6821, 6841, 6851, 6861, 6871 with Multiplatform Firmware
  • IP Phone 7811, 7821, 7841, 7861 Desktop Phones
  • IP Phone 7811, 7821, 7841, 7861 Desktop Phones with Multiplatform Firmware
  • IP Phone 8811, 8841, 8851, 8861, 8845, 8865 Desktop Phones
  • IP Phone 8811, 8841, 8851, 8861, 8845, 8865 Desktop Phones with Multiplatform Firmware
  • Unified IP Conference Phone 8831
  • Unified IP Conference Phone 8831 for Third-Party Call Control
  • Wireless IP Phone 8821, 8821-EX
  • Cisco SPA525G 5-Line IP Phone

  Cisco Discovery Protocol and LLDP are enabled by default on most IP Phone models.

  For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

  Products Confirmed Not Vulnerable

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by these vulnerabilities.

  Cisco has confirmed that these vulnerabilities do not affect the following Cisco products:

  • Cisco Unified IP Phone 6901
  • Cisco Unified IP Phone 6911
  • Cisco ATA 191 Analog Telephone Adapter
  • Cisco ATA 190 Analog Telephone Adapter
  • Webex Room Phone
  • Cisco Unified IP Phone 3905
  • Cisco SPA112 2-Port Phone Adapter
  • Cisco SPA122 Analog Telephone Adapter (ATA) with Router
  • Cisco SPA232D Multi-Line DECT Analog Telephone Adapter (ATA)
  • Cisco IP DECT 6800 Series with Multiplatform Firmware

Workarounds

• There are no workarounds that address these vulnerabilities.

Fixed Software

• When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Fixed Releases

  At the time of publication, the release information in the following table(s) was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

  The left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerabilities described in this advisory and which release included the fix for these vulnerabilities.

  Cisco IP Phone Model	Cisco Bug ID	First Fixed Release
  IP Conference Phone 8832 with Multiplatform Firmware IP Conference Phone 7832 with Multiplatform Firmware IP Phone 6821, 6841, 6851, 6861, 6871 with Multiplatform Firmware IP Phone 7811, 7821, 7841, 7861 Desktop Phones with Multiplatform Firmware IP Phone 8811, 8841, 8851, 8861, 8845, 8865 Desktop Phones with Multiplatform Firmware	CSCvu59335	11.3(2)
  IP Phone 8811, 8841, 8851, 8861, 8845, 8865 Desktop Phones IP Conference Phone 7832 IP Conference Phone 8832 IP Phone 7811, 7821, 7841, 7861 Desktop Phones	CSCvu59349	12.8(1)SR1
  Unified IP Conference Phone 8831	CSCvu59346	10.3(1)SR7. Target release May 2021
  Unified IP Conference Phone 8831 for Third-Party Call Control	CSCvu59330	There is no fixed firmware available at this time.
  SPA525G 5-Line IP Phone	CSCvu59329	There is no fixed firmware available at this time.
  Cisco Unified IP Phone 7900 Series	CSCvu59353	There is no fixed firmware available at this time.
  Wireless IP Phone 8821 and 8821-EX	CSCvu59351	11.0(6.6)

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

Source

• Cisco would like to thank Qian Chen of Qihoo 360 Nirvan Team for reporting these vulnerabilities.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipphone-rce-dos-U2PsSkz3

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2021-MAR-03

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