From 239f8d93866605b05f4e6b551f4327dc7fcb922b Mon Sep 17 00:00:00 2001 From: Viktor Szakats Date: Tue, 23 Feb 2021 14:54:46 +0100 Subject: [PATCH 1/2] 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 Upstream-commit: 7214288898f5625a6cc196e22a74232eada7861c Signed-off-by: Kamil Dudka --- lib/transfer.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/lib/transfer.c b/lib/transfer.c index ecd1063..263b178 100644 --- a/lib/transfer.c +++ b/lib/transfer.c @@ -1473,6 +1473,7 @@ CURLcode Curl_follow(struct Curl_easy *data, /* Location: redirect */ bool disallowport = FALSE; bool reachedmax = FALSE; + CURLUcode uc; if(type == FOLLOW_REDIR) { if((data->set.maxredirs != -1) && @@ -1488,6 +1489,9 @@ CURLcode Curl_follow(struct Curl_easy *data, data->set.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 */ @@ -1497,9 +1501,26 @@ CURLcode Curl_follow(struct Curl_easy *data, data->change.referer_alloc = FALSE; } - data->change.referer = strdup(data->change.url); - if(!data->change.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->change.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->change.referer = referer; data->change.referer_alloc = TRUE; /* yes, free this later */ } } -- 2.30.2 From f7d1d478b87499ce31d6aa3251830b78447ad952 Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Mon, 29 Mar 2021 09:32:14 +0200 Subject: [PATCH 2/2] transfer: clear 'referer' in declaration To silence (false positive) compiler warnings about it. Follow-up to 7214288898f5625 Reviewed-by: Marcel Raad Closes #6810 Upstream-commit: 6bb028dbda6cbfe83f66de773544f71e4813160f Signed-off-by: Kamil Dudka --- lib/transfer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/transfer.c b/lib/transfer.c index 263b178..ad5a7ba 100644 --- a/lib/transfer.c +++ b/lib/transfer.c @@ -1490,7 +1490,7 @@ CURLcode Curl_follow(struct Curl_easy *data, if(data->set.http_auto_referer) { CURLU *u; - char *referer; + char *referer = NULL; /* 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 @@ -1518,7 +1518,7 @@ CURLcode Curl_follow(struct Curl_easy *data, curl_url_cleanup(u); - if(uc || referer == NULL) + if(uc || !referer) return CURLE_OUT_OF_MEMORY; data->change.referer = referer; data->change.referer_alloc = TRUE; /* yes, free this later */ -- 2.30.2