Avoid index out of range panic on malformed request URIs#96
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AruneshDwivedi wants to merge 1 commit into
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Avoid index out of range panic on malformed request URIs#96AruneshDwivedi wants to merge 1 commit into
AruneshDwivedi wants to merge 1 commit into
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When PathSource is RequestURI, stripping the query string from a value like "?" collapses the path to an empty string, after which path[pathLen-1] and path[1:] index out of range and panic. Requests whose path is empty or lacks a leading slash cannot match any route, so lookup now returns not found for them instead of indexing past the slice.
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Fixes #88.
When
PathSourceisRequestURI(the default),lookupstrips the query string from the request URI before searching. A malformed request line such as a bare?has no path, so after the strippathbecomes""withpathLen0. The code then evaluatespath[pathLen-1]for the trailing slash check andpath[1:]for the tree search, both of which index out of range and panic. Vulnerability scanners hit this routinely with junk URLs, which is how the reporter saw it through theirLookupFuncbased SPA fallback.A request whose path is empty or does not start with a slash can never match a registered route, so
lookupnow returns not found for it before doing any slice indexing.Added
TestLookupMalformedRequestURIcovering?,*, and a path with no leading slash, all of which panicked before this change.