1From 62c09239ac4e08239c8e363b06901fc80637d8c7 Mon Sep 17 00:00:00 2001 2From: Daniel Stenberg <daniel@haxx.se> 3Date: Mon, 29 Aug 2022 00:09:17 +0200 4Subject: [PATCH] cookie: reject cookies with "control bytes" 5 6Rejects 0x01 - 0x1f (except 0x09) plus 0x7f 7 8Reported-by: Axel Chong 9 10Bug: https://curl.se/docs/CVE-2022-35252.html 11 12CVE-2022-35252 13 14Closes #9381 15 16Upstream-Status: Backport [https://github.com/curl/curl/commit/8dfc93e573ca740544a2d79ebb] 17 18Signed-off-by: Robert Joslyn <robert.joslyn@redrectangle.org> 19--- 20 lib/cookie.c | 29 +++++++++++++++++++++++++++++ 21 1 file changed, 29 insertions(+) 22 23diff --git a/lib/cookie.c b/lib/cookie.c 24index cb0c03b..e0470a1 100644 25--- a/lib/cookie.c 26+++ b/lib/cookie.c 27@@ -438,6 +438,30 @@ static bool bad_domain(const char *domain) 28 return TRUE; 29 } 30 31+/* 32+ RFC 6265 section 4.1.1 says a server should accept this range: 33+ 34+ cookie-octet = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E 35+ 36+ But Firefox and Chrome as of June 2022 accept space, comma and double-quotes 37+ fine. The prime reason for filtering out control bytes is that some HTTP 38+ servers return 400 for requests that contain such. 39+*/ 40+static int invalid_octets(const char *p) 41+{ 42+ /* Reject all bytes \x01 - \x1f (*except* \x09, TAB) + \x7f */ 43+ static const char badoctets[] = { 44+ "\x01\x02\x03\x04\x05\x06\x07\x08\x0a" 45+ "\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14" 46+ "\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x7f" 47+ }; 48+ size_t vlen, len; 49+ /* scan for all the octets that are *not* in cookie-octet */ 50+ len = strcspn(p, badoctets); 51+ vlen = strlen(p); 52+ return (len != vlen); 53+} 54+ 55 /* 56 * Curl_cookie_add 57 * 58@@ -590,6 +614,11 @@ Curl_cookie_add(struct Curl_easy *data, 59 badcookie = TRUE; 60 break; 61 } 62+ if(invalid_octets(whatptr) || invalid_octets(name)) { 63+ infof(data, "invalid octets in name/value, cookie dropped"); 64+ badcookie = TRUE; 65+ break; 66+ } 67 } 68 else if(!len) { 69 /* 70-- 712.35.1 72 73