Fix ReDOS in cpp/ql/src/Security/CWE/CWE-428/UnsafeCreateProcessCall.ql #5613
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The sub-regex `(\s|.)*` aims to capture arbitrary string content (in contrast to `.*` which doesn't match newlines), but it is unsafe, since non-newline whitespace can match both alternatives. This caused an evaluator crash in the wild. Replace with `[\s\S]*`, which matches everything in a safe way.
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Looks good to me, but do we need a change note for this? |
My immediate gut feeling is no. (But that isn't my decision). I think the problem only triggers for codebases that contain very long string literals with a lot of whitespace in them. So it's a fix for a quite rare failure, which shouldn't have any effects other than this query no longer crashes QL ... |
rdmarsh2
approved these changes
Apr 6, 2021
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The sub-regex
(\s|.)*aims to capture arbitrary string content (in contrast to.*which doesn't match newlines), but it is unsafe, since non-newline whitespace can match both alternatives.This caused an evaluator crash in the wild.
Replace with
[\s\S]*, which matches everything in a safe way.