A flaw was found in JBossWeb in versions before 7.5.31.Final-redhat-3. The fix for CVE-2020-13935 was incomplete in JBossWeb, leaving it vulnerable to a denial of service attack when sending multiple requests with invalid payload length in a WebSocket frame. The highest threat from this vulnerability is to system availability.

JBoss Web will enter into an infinite loop when a surrogate pair character is placed at the boundary of an internal buffer. A remote attacker could exploit this flaw to trigger a denial-of-service attack against a JBoss Web server that is hosting applications with UTF-8 character encoding enabled, or that will include user-supplied UTF-8 strings in a response.