User controlled request.getHeader("Referer"), request.getRequestURL() and request.getQueryString() are used to build and run a regex expression. The attacker doesn't have to use a browser and may send a specially crafted Referer header programmatically. Since the attacker controls the string and the regex pattern he may cause a ReDoS by regex catastrophic backtracking on the server side. This problem has been fixed in Roller 6.0.2.
{
"cpe": "cpe:2.3:a:apache:roller:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "6.0.2"
}
],
"source": "CPE_RANGE"
}