What’s Vulnerable › Vulnerabilities

CVE-2019-1635: Cisco IP Phone 7800 Series and 8800 Series Session Initiation Protocol XML Denial of Service Vulnerability

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-05-03 · updated 2026-06-17
• Weakness: CWE-399

Description

A vulnerability in the call-handling functionality of Session Initiation Protocol (SIP) Software for Cisco IP Phone 7800 Series and 8800 Series could allow an unauthenticated, remote attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability is due to incomplete error handling when XML data within a SIP packet is parsed. An attacker could exploit this vulnerability by sending a SIP packet that contains a malicious XML payload to an affected phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition.

Affected products

• Cisco Ip Conference Phone 7832 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Conference Phone 8832 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 7811 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 7821 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 7841 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 7861 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 8811 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 8841 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 8845 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 8851 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 8861 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Ip Phone 8865 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Unified Ip 8831 Conference Phone1 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Unified Ip 8831 Conference Phone For Third-Party Call Control2 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Wireless Ip Phone 8821-Ex Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1
• Cisco Wireless Ip Phone 8821 Firmware: 9.3(4)sr3, 10.3(1)sr4b, 11.0(4)sr2, 12.1(1)sr1

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-phone-sip-xml-dos
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-phone-sip-xml-dos

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