fix: skip duplicate HTTP status lines in ReadResponse#542
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Mzack9999 merged 2 commits intoJun 16, 2026
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Some non-compliant servers (e.g. Grandstream HT801 firmware 1.0.13.7) emit the HTTP status line more than once before the actual headers: HTTP/1.0 200 OK\r\n HTTP/1.0 200 OK\r\n <- duplicate Content-Type: text/html\r\n ... The rawhttp parser passes header lines to ReadHeader(), which splits on ':'. A duplicate status line has no ':', so parsing fails with: malformed MIME header: missing colon: "HTTP/1.0 200 OK" This propagates to Nuclei as a fatal request error even under unsafe: true, preventing matchers from ever running. Fix: after reading the first status line in ReadResponse(), peek ahead and discard any additional lines that start with 'HTTP/' before entering the header-reading loop. Adds regression tests for duplicate and triple status lines. Fixes projectdiscovery#541 Related: projectdiscovery/nuclei#7363
Mzack9999
approved these changes
Jun 16, 2026
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Problem
Some non-compliant servers (e.g. Grandstream HT801 firmware 1.0.13.7) emit the HTTP status line more than once before actual headers:
ReadHeader()splits on:. A repeated status line has no:, so parsing fails with:This error propagates to Nuclei as a fatal request error even under
unsafe: true, preventing matchers from ever running.Fix
After reading the first status line in
ReadResponse(), peek ahead and discard any additional lines that start withHTTP/before entering the header-reading loop. The change is minimal (< 15 lines) and touches only the one code path.Tests
Two new regression tests added to
client/reader_test.go:TestReadResponseDuplicateStatusLines— double status line with a bodyTestReadResponseTripleStatusLines— triple status lineAll existing tests continue to pass (
go test ./...).Related