How can I trigger a Regex-DOS using the preg_match() function using an evil regular expression (e.g. (a+)+ )?
For example, I have the following situation:
preg_match('/(a+)+/',$input);
If I have control over $input, how could I trigger a DOS attack or reach the backtrack limit of the preg_* f...
@Zachiel That probably needs more details to be a clear question, but I suspect you're talking about an anti-CSRF token, that exists both in the session (could be the session id) and in the form itself. Is that correct?
I strongly recommend blocking non-Stack-hosted images in posts going forward. The potential harm may not be severe, but it exists and there is no benefit to balance it out.
Reasons to leave them:
To avoid inconveniencing editors of old posts, as we already do with shorted URLs.
Nothing else?
...
How can I trigger a Regex-DOS using the preg_match() function using an evil regular expression (e.g. (a+)+ )?
For example, I have the following situation:
preg_match('/(a+)+/',$input);
If I have control over $input, how could I trigger a DOS attack or reach the backtrack limit of the preg_* f...
I strongly recommend blocking non-Stack-hosted images in posts going forward. The potential harm may not be severe, but it exists and there is no benefit to balance it out.
Reasons to leave them:
To avoid inconveniencing editors of old posts, as we already do with shorted URLs.
Nothing else?
...
