| From e12531340b03d242d3f892aa8797faf12b56dddf Mon Sep 17 00:00:00 2001 |
| From: Daniel Stenberg <daniel@haxx.se> |
| Date: Mon, 16 May 2022 16:28:13 +0200 |
| Subject: [PATCH] content_encoding: return error on too many compression steps |
| |
| The max allowed steps is arbitrarily set to 5. |
| |
| Bug: https://curl.se/docs/CVE-2022-32206.html |
| CVE-2022-32206 |
| Reported-by: Harry Sintonen |
| Closes #9049 |
| |
| Upstream-Status: Backport [https://github.com/curl/curl/commit/3a09fbb7f264c67c43] |
| Signed-off-by: Robert Joslyn <robert.joslyn@redrectangle.org> |
| --- |
| lib/content_encoding.c | 9 +++++++++ |
| 1 file changed, 9 insertions(+) |
| |
| diff --git a/lib/content_encoding.c b/lib/content_encoding.c |
| index c03637a..6f994b3 100644 |
| --- a/lib/content_encoding.c |
| +++ b/lib/content_encoding.c |
| @@ -1026,12 +1026,16 @@ static const struct content_encoding *find_encoding(const char *name, |
| return NULL; |
| } |
| |
| +/* allow no more than 5 "chained" compression steps */ |
| +#define MAX_ENCODE_STACK 5 |
| + |
| /* Set-up the unencoding stack from the Content-Encoding header value. |
| * See RFC 7231 section 3.1.2.2. */ |
| CURLcode Curl_build_unencoding_stack(struct Curl_easy *data, |
| const char *enclist, int maybechunked) |
| { |
| struct SingleRequest *k = &data->req; |
| + int counter = 0; |
| |
| do { |
| const char *name; |
| @@ -1066,6 +1070,11 @@ CURLcode Curl_build_unencoding_stack(struct Curl_easy *data, |
| if(!encoding) |
| encoding = &error_encoding; /* Defer error at stack use. */ |
| |
| + if(++counter >= MAX_ENCODE_STACK) { |
| + failf(data, "Reject response due to %u content encodings", |
| + counter); |
| + return CURLE_BAD_CONTENT_ENCODING; |
| + } |
| /* Stack the unencoding stage. */ |
| writer = new_unencoding_writer(data, encoding, k->writer_stack); |
| if(!writer) |