A vulnerability in Cisco Webex Network Recording Player and Cisco Webex Player for Microsoft Windows could allow an attacker to cause a process crash resulting in a Denial of service (DoS) condition for the player application on an affected system. The vulnerability exists due to insufficient validation of certain elements with a Webex recording stored in either the Advanced Recording Format (ARF) or the Webex Recording Format (WRF). An attacker could exploit this vulnerability by sending a user a malicious ARF or WRF file through a link or email attachment and persuading the user to open the file with the affected software on the local system. A successful exploit could allow the attacker to cause the Webex player application to crash when trying to view the malicious file. This vulnerability affects Cisco Webex Network Recording Player and Webex Player releases earlier than Release 3.0 MR3 Security Patch 2 and 4.0 MR3.