CWE-1333: Inefficient Regular Expression Complexity

Extended Description

Some regular expression engines have a feature called "backtracking". If the token cannot match, the engine "backtracks" to a position that may result in a different token that can match. Backtracking becomes a weakness if all of these conditions are met: The number of possible backtracking attempts are exponential relative to the length of the input. The input can fail to match the regular expression. The input can be long enough. Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.