Cisco Firepower Threat Defense Software DNS Enforcement Denial of Service Vulnerability<p>A vulnerability in the Snort rule evaluation function of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.</p>
<p>The vulnerability is due to improper handling of the DNS reputation enforcement rule. An attacker could exploit this vulnerability by sending crafted UDP packets through an affected device to force a buildup of UDP connections. A successful exploit could allow the attacker to cause traffic that is going through the affected device to be dropped, resulting in a DoS condition. </p>
<p><strong>Note:</strong> This vulnerability only affects Cisco FTD devices that are running Snort 3.</p>
<p>Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.</p>
<p>This advisory is available at the following link:<br><a href="https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-FTD-snort3-DOS-Aq38LVdM">https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-FTD-snort3-DOS-Aq38LVdM</a></p>
<p>This advisory is part of the April 2022 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see <a href="https://tools.cisco.com/security/center/viewErp.x?alertId=ERP-74836">Cisco Event Response: April 2022 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication</a>.</p>
Security Impact Rating: High
CVE: CVE-2022-20767
Source: Cisco Firepower Threat Defense Software DNS Enforcement Denial of Service Vulnerability (https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-FTD-snort3-DOS-Aq38LVdM?vs_f=Cisco%20Security%20Advisory&vs_cat=Security%20Intelligence&vs_type=RSS&vs_p=Cisco%20Firepower%20Threat%20Defense%20Software%20DNS%20Enforcement%20Denial%20of%20Service%20Vulnerability&vs_k=1)