From 7214288898f5625a6cc196e22a74232eada7861c Mon Sep 17 00:00:00 2001 From: Viktor Szakats Date: Tue, 23 Feb 2021 14:54:46 +0100 Subject: transfer: strip credentials from the auto-referer header field Added test 2081 to verify. CVE-2021-22876 Bug: https://curl.se/docs/CVE-2021-22876.html --- lib/transfer.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) (limited to 'lib/transfer.c') diff --git a/lib/transfer.c b/lib/transfer.c index 1976bc033..a68c021c8 100644 --- a/lib/transfer.c +++ b/lib/transfer.c @@ -1581,6 +1581,9 @@ CURLcode Curl_follow(struct Curl_easy *data, data->state.followlocation++; /* count location-followers */ if(data->set.http_auto_referer) { + CURLU *u; + char *referer; + /* We are asked to automatically set the previous URL as the referer when we get the next URL. We pick the ->url field, which may or may not be 100% correct */ @@ -1590,9 +1593,27 @@ CURLcode Curl_follow(struct Curl_easy *data, data->state.referer_alloc = FALSE; } - data->state.referer = strdup(data->state.url); - if(!data->state.referer) + /* Make a copy of the URL without crenditals and fragment */ + u = curl_url(); + if(!u) + return CURLE_OUT_OF_MEMORY; + + uc = curl_url_set(u, CURLUPART_URL, data->state.url, 0); + if(!uc) + uc = curl_url_set(u, CURLUPART_FRAGMENT, NULL, 0); + if(!uc) + uc = curl_url_set(u, CURLUPART_USER, NULL, 0); + if(!uc) + uc = curl_url_set(u, CURLUPART_PASSWORD, NULL, 0); + if(!uc) + uc = curl_url_get(u, CURLUPART_URL, &referer, 0); + + curl_url_cleanup(u); + + if(uc || referer == NULL) return CURLE_OUT_OF_MEMORY; + + data->state.referer = referer; data->state.referer_alloc = TRUE; /* yes, free this later */ } } -- cgit v1.2.1