From 62c09239ac4e08239c8e363b06901fc80637d8c7 Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Mon, 29 Aug 2022 00:09:17 +0200 Subject: [PATCH] cookie: reject cookies with "control bytes" Rejects 0x01 - 0x1f (except 0x09) plus 0x7f Reported-by: Axel Chong Bug: https://curl.se/docs/CVE-2022-35252.html CVE-2022-35252 Closes #9381 Upstream-Status: Backport [https://github.com/curl/curl/commit/8dfc93e573ca740544a2d79ebb] Signed-off-by: Robert Joslyn --- lib/cookie.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/lib/cookie.c b/lib/cookie.c index cb0c03b..e0470a1 100644 --- a/lib/cookie.c +++ b/lib/cookie.c @@ -438,6 +438,30 @@ static bool bad_domain(const char *domain) return TRUE; } +/* + RFC 6265 section 4.1.1 says a server should accept this range: + + cookie-octet = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E + + But Firefox and Chrome as of June 2022 accept space, comma and double-quotes + fine. The prime reason for filtering out control bytes is that some HTTP + servers return 400 for requests that contain such. +*/ +static int invalid_octets(const char *p) +{ + /* Reject all bytes \x01 - \x1f (*except* \x09, TAB) + \x7f */ + static const char badoctets[] = { + "\x01\x02\x03\x04\x05\x06\x07\x08\x0a" + "\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14" + "\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x7f" + }; + size_t vlen, len; + /* scan for all the octets that are *not* in cookie-octet */ + len = strcspn(p, badoctets); + vlen = strlen(p); + return (len != vlen); +} + /* * Curl_cookie_add * @@ -590,6 +614,11 @@ Curl_cookie_add(struct Curl_easy *data, badcookie = TRUE; break; } + if(invalid_octets(whatptr) || invalid_octets(name)) { + infof(data, "invalid octets in name/value, cookie dropped"); + badcookie = TRUE; + break; + } } else if(!len) { /* -- 2.35.1