Cisco IP Phones with Multiplatform Cisco Discovery Protocol buffer overflow

Summaryinfo

A vulnerability labeled as critical has been found in Cisco IP Phones with Multiplatform, Session Initiation Protocol Software and Small Business IP Phones. This impacts an unknown function of the component Cisco Discovery Protocol/Link Layer Discovery Protocol. Such manipulation leads to buffer overflow. This vulnerability is listed as CVE-2021-1379. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Cisco IP Phones with Multiplatform, Session Initiation Protocol Software and Small Business IP Phones (the affected version unknown) and classified as critical. Affected by this issue is an unknown part of the component Cisco Discovery Protocol/Link Layer Discovery Protocol. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is availability. CVE summarizes:

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.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability is handled as CVE-2021-1379 since 11/13/2020. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 01/06/2026).

Upgrading eliminates this vulnerability.

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Productinfo

Type

• IP Phone Software

Vendor

• Cisco

Name

• IP Phones with Multiplatform
• Session Initiation Protocol Software
• Small Business IP Phones

License

• commercial

Website

• Vendor: https://www.cisco.com/

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