A vulnerability in the API Framework of Cisco AsyncOS for Cisco Web Security Appliance (WSA) and Cisco Content Security Management Appliance (SMA) could allow an unauthenticated, remote attacker to inject crafted HTTP headers in the web server's response. The vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by persuading a user to access a crafted URL and receive a malicious HTTP response. A successful exploit could allow the attacker to inject arbitrary HTTP headers into valid HTTP responses sent to a user's browser.