fix: avoid out-of-bounds read when parsing the response status line#2464
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alexandre-daubois merged 1 commit intoJun 26, 2026
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alexandre-daubois
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dunglas
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frankenphp_send_headers parsed the status code with
atoi(SG(sapi_headers).http_status_line + 9), assuming a fixed
"HTTP/x.y " 9-byte prefix. A script setting a shorter status line, e.g.
header("HTTP/"), leaves http_status_line only 5 bytes long, so the +9
offset reads past the buffer. Confirmed with AddressSanitizer
(heap-buffer-overflow read in atoi, 3 bytes past a 6-byte estrndup'd
region) via an embed build with USE_ZEND_ALLOC=0.
PHP already parses the code into http_response_code through
sapi_update_response_code() whenever a status line is set, so the
reparse was redundant as well as unsafe. Use http_response_code
directly.
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frankenphp_send_headersparsed the status withatoi(http_status_line + 9), assuming a fixed 9-byte"HTTP/x.y "prefix.header("HTTP/")(5 bytes) makes+9read past the buffer. ASan confirms a heap-buffer-overflow read inatoi, 3 bytes past theestrndup'd line.PHP already parses the code into
http_response_code(viasapi_update_response_code()), so the reparse was redundant and unsafe. Use it directly. Tests instatusline_test.go(run under-asan) cover the short line and a validHTTP/1.1 418line.