A vulnerability in the XML parser code of Cisco Firepower Device Manager On-Box software could allow an authenticated, remote attacker to cause an affected system to become unstable or reload. The vulnerability is due to insufficient hardening of the XML parser configuration. An attacker could exploit this vulnerability in multiple ways using a malicious file: An attacker with administrative privileges could upload a malicious XML file on the system and cause the XML code to parse the malicious file. An attacker with Clientless Secure Sockets Layer (SSL) VPN access could exploit this vulnerability by sending a crafted XML file. A successful exploit would allow the attacker to crash the XML parser process, which could cause system instability, memory exhaustion, and in some cases lead to a reload of the affected system.