cookies: only use full host matches for hosts used as IP address

By not detecting and rejecting domain names for partial literal IP
addresses properly when parsing received HTTP cookies, libcurl can be
fooled to both send cookies to wrong sites and to allow arbitrary sites
to set cookies for others.

CVE-2014-3613

Bug: http://curl.haxx.se/docs/adv_20140910A.html

1 files changed, 40 insertions, 10 deletions

diff --git a/lib/cookie.c b/lib/cookie.c
index 059064348..46904ac57 100644
--- a/lib/cookie.c
+++ b/lib/cookie.c
@@ -95,6 +95,7 @@ Example set of cookies:
 #include "strtoofft.h"
 #include "rawstr.h"
 #include "curl_memrchr.h"
+#include "inet_pton.h"
 
 /* The last #include file should be: */
 #include "memdebug.h"
@@ -319,6 +320,28 @@ static void remove_expired(struct CookieInfo *cookies)
   }
 }
 
+/*
+ * Return true if the given string is an IP(v4|v6) address.
+ */
+static bool isip(const char *domain)
+{
+  struct in_addr addr;
+#ifdef ENABLE_IPV6
+  struct in6_addr addr6;
+#endif
+
+  if(Curl_inet_pton(AF_INET, domain, &addr)
+#ifdef ENABLE_IPV6
+     || Curl_inet_pton(AF_INET6, domain, &addr6)
+#endif
+    ) {
+    /* domain name given as IP address */
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
 /****************************************************************************
  *
  * Curl_cookie_add()
@@ -439,24 +462,27 @@ Curl_cookie_add(struct SessionHandle *data,
           }
         }
         else if(Curl_raw_equal("domain", name)) {
+          bool is_ip;
+
           /* Now, we make sure that our host is within the given domain,
              or the given domain is not valid and thus cannot be set. */
 
           if('.' == whatptr[0])
             whatptr++; /* ignore preceding dot */
 
-          if(!domain || tailmatch(whatptr, domain)) {
-            const char *tailptr=whatptr;
-            if(tailptr[0] == '.')
-              tailptr++;
-            strstore(&co->domain, tailptr); /* don't prefix w/dots
-                                               internally */
+          is_ip = isip(domain ? domain : whatptr);
+
+          if(!domain
+             || (is_ip && !strcmp(whatptr, domain))
+             || (!is_ip && tailmatch(whatptr, domain))) {
+            strstore(&co->domain, whatptr);
             if(!co->domain) {
               badcookie = TRUE;
               break;
             }
-            co->tailmatch=TRUE; /* we always do that if the domain name was
-                                   given */
+            if(!is_ip)
+              co->tailmatch=TRUE; /* we always do that if the domain name was
+                                     given */
           }
           else {
             /* we did not get a tailmatch and then the attempted set domain
@@ -968,6 +994,7 @@ struct Cookie *Curl_cookie_getlist(struct CookieInfo *c,
   time_t now = time(NULL);
   struct Cookie *mainco=NULL;
   size_t matches = 0;
+  bool is_ip;
 
   if(!c || !c->cookies)
     return NULL; /* no cookie struct or no cookies in the struct */
@@ -975,6 +1002,9 @@ struct Cookie *Curl_cookie_getlist(struct CookieInfo *c,
   /* at first, remove expired cookies */
   remove_expired(c);
 
+  /* check if host is an IP(v4|v6) address */
+  is_ip = isip(host);
+
   co = c->cookies;
 
   while(co) {
@@ -986,8 +1016,8 @@ struct Cookie *Curl_cookie_getlist(struct CookieInfo *c,
 
       /* now check if the domain is correct */
       if(!co->domain ||
-         (co->tailmatch && tailmatch(co->domain, host)) ||
-         (!co->tailmatch && Curl_raw_equal(host, co->domain)) ) {
+         (co->tailmatch && !is_ip && tailmatch(co->domain, host)) ||
+         ((!co->tailmatch || is_ip) && Curl_raw_equal(host, co->domain)) ) {
         /* the right part of the host matches the domain stuff in the
            cookie data */