Untrusted data is passed to the application and used as a regular expression. This can cause the thread to over-consume CPU resources.
Where separator is provided by CacheControlHeader:
There is a vulnerability in implementations of regular expression evaluators and related methods that can cause the thread to hang when evaluating repeating and alternating overlapping of nested and repeated regex groups. This defect can be used to execute a DOS (Denial of Service) attack.
There are no known regular expression implementations which are immune to this vulnerability.