diff -uNr '--exclude=*~' curl-7.21.5/lib/escape.c curl-7.21.5-url-sanitize/lib/escape.c
--- curl-7.21.5/lib/escape.c	2011-03-19 11:17:13.000000000 -0400
+++ curl-7.21.5-url-sanitize/lib/escape.c	2012-01-27 22:36:54.066212151 -0500
@@ -35,6 +35,7 @@
 #include "urldata.h"
 #include "easyif.h"
 #include "warnless.h"
+#include "escape.h"
 
 #define _MPRINTF_REPLACE /* use our functions only */
 #include <curl/mprintf.h>
@@ -88,7 +89,7 @@
   char *testing_ptr = NULL;
   unsigned char in; /* we need to treat the characters unsigned */
   size_t newlen = alloc;
-  int strindex=0;
+  size_t strindex=0;
   size_t length;
 
 #ifndef CURL_DOES_CONVERSIONS
@@ -143,26 +144,27 @@
 }
 
 /*
- * Unescapes the given URL escaped string of given length. Returns a
- * pointer to a malloced string with length given in *olen.
- * If length == 0, the length is assumed to be strlen(string).
- * If olen == NULL, no output length is stored.
+ * Curl_urldecode() URL decodes the given string.
+ * 
+ * Optionally detects control characters (byte codes lower than 32) in the
+ * data and rejects such data.
+ * 
+ * Returns a pointer to a malloced string in *ostring with length given in
+ * *olen. If length == 0, the length is assumed to be strlen(string).
  */
-char *curl_easy_unescape(CURL *handle, const char *string, int length,
-                         int *olen)
+CURLcode Curl_urldecode(struct SessionHandle *data,
+			const char *string, size_t length,
+			char **ostring, size_t *olen,
+			bool reject_ctrl)
 {
-  int alloc = (length?length:(int)strlen(string))+1;
+  size_t alloc = (length?length:strlen(string))+1;
   char *ns = malloc(alloc);
   unsigned char in;
-  int strindex=0;
+  size_t strindex=0;
   unsigned long hex;
 
-#ifndef CURL_DOES_CONVERSIONS
-  /* avoid compiler warnings */
-  (void)handle;
-#endif
   if( !ns )
-    return NULL;
+    return CURLE_OUT_OF_MEMORY;
 
   while(--alloc > 0) {
     in = *string;
@@ -181,16 +183,20 @@
 #ifdef CURL_DOES_CONVERSIONS
 /* escape sequences are always in ASCII so convert them on non-ASCII hosts */
       if(!handle ||
-          (Curl_convert_from_network(handle, &in, 1) != CURLE_OK)) {
+          (Curl_convert_from_network(data, &in, 1) != CURLE_OK)) {
         /* Curl_convert_from_network calls failf if unsuccessful */
         free(ns);
-        return NULL;
+        return res;
       }
 #endif /* CURL_DOES_CONVERSIONS */
 
       string+=2;
       alloc-=2;
     }
+    if(reject_ctrl && (in < 0x20)) {
+      free(ns);
+      return CURLE_URL_MALFORMAT;
+    }
 
     ns[strindex++] = in;
     string++;
@@ -200,7 +206,33 @@
   if(olen)
     /* store output size */
     *olen = strindex;
-  return ns;
+
+  if(ostring)
+    /* store output string */
+    *ostring = ns;
+
+  return CURLE_OK;
+}
+
+/*
+ * Unescapes the given URL escaped string of given length. Returns a
+ * pointer to a malloced string with length given in *olen.
+ * If length == 0, the length is assumed to be strlen(string).
+ * If olen == NULL, no output length is stored.
+ */
+char *curl_easy_unescape(CURL *handle, const char *string, int length,
+			 int *olen)
+{
+  char *str = NULL;
+  size_t inputlen = length;
+  size_t outputlen;
+  CURLcode res = Curl_urldecode(handle, string, inputlen, &str, &outputlen,
+				FALSE);
+  if(res)
+    return NULL;
+  if(olen)
+    *olen = curlx_uztosi(outputlen);
+  return str;
 }
 
 /* For operating systems/environments that use different malloc/free
diff -uNr '--exclude=*~' curl-7.21.5/lib/escape.h curl-7.21.5-url-sanitize/lib/escape.h
--- curl-7.21.5/lib/escape.h	2011-03-19 11:16:07.000000000 -0400
+++ curl-7.21.5-url-sanitize/lib/escape.h	2012-01-27 22:11:59.980378902 -0500
@@ -8,7 +8,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -25,5 +25,9 @@
 /* Escape and unescape URL encoding in strings. The functions return a new
  * allocated string or NULL if an error occurred.  */
 
+CURLcode Curl_urldecode(struct SessionHandle *data,
+			const char *string, size_t length,
+			char **ostring, size_t *olen,
+			bool reject_crlf);
 
 #endif
diff -uNr '--exclude=*~' curl-7.21.5/lib/imap.c curl-7.21.5-url-sanitize/lib/imap.c
--- curl-7.21.5/lib/imap.c	2011-04-04 18:04:47.000000000 -0400
+++ curl-7.21.5-url-sanitize/lib/imap.c	2012-01-27 22:12:42.934298897 -0500
@@ -953,17 +953,12 @@
   struct imap_conn *imapc = &conn->proto.imapc;
   struct SessionHandle *data = conn->data;
   const char *path = data->state.path;
-  int len;
 
   if(!*path)
     path = "INBOX";
 
   /* url decode the path and use this mailbox */
-  imapc->mailbox = curl_easy_unescape(data, path, 0, &len);
-  if(!imapc->mailbox)
-    return CURLE_OUT_OF_MEMORY;
-
-  return CURLE_OK;
+  return Curl_urldecode(data, path, 0, &imapc->mailbox, NULL, TRUE);
 }
 
 /* call this when the DO phase has completed */
diff -uNr '--exclude=*~' curl-7.21.5/lib/pop3.c curl-7.21.5-url-sanitize/lib/pop3.c
--- curl-7.21.5/lib/pop3.c	2011-04-05 11:07:17.000000000 -0400
+++ curl-7.21.5-url-sanitize/lib/pop3.c	2012-01-27 22:13:32.857586724 -0500
@@ -897,11 +897,7 @@
   const char *path = data->state.path;
 
   /* url decode the path and use this mailbox */
-  pop3c->mailbox = curl_easy_unescape(data, path, 0, NULL);
-  if (!pop3c->mailbox)
-    return CURLE_OUT_OF_MEMORY;
-
-  return CURLE_OK;
+  return Curl_urldecode(data, path, 0, &pop3c->mailbox, NULL, TRUE);
 }
 
 /* call this when the DO phase has completed */
diff -uNr '--exclude=*~' curl-7.21.5/lib/smtp.c curl-7.21.5-url-sanitize/lib/smtp.c
--- curl-7.21.5/lib/smtp.c	2011-04-04 18:04:47.000000000 -0400
+++ curl-7.21.5-url-sanitize/lib/smtp.c	2012-01-27 22:15:21.847977858 -0500
@@ -1097,7 +1097,6 @@
   struct SessionHandle *data=conn->data;
   struct pingpong *pp=&smtpc->pp;
   const char *path = conn->data->state.path;
-  int len;
   char localhost[1024 + 1];
 
   *done = FALSE; /* default to not done yet */
@@ -1169,9 +1168,9 @@
   }
 
   /* url decode the path and use it as domain with EHLO */
-  smtpc->domain = curl_easy_unescape(conn->data, path, 0, &len);
-  if(!smtpc->domain)
-    return CURLE_OUT_OF_MEMORY;
+  result = Curl_urldecode(conn->data, path, 0, &smtpc->domain, NULL, TRUE);
+  if(result)
+    return result;
 
   /* When we connect, we start in the state where we await the server greeting
    */