[curl/f15] reject URLs containing bad data (CVE-2012-0036)

Kamil Dudka kdudka at fedoraproject.org
Tue Jan 24 12:30:59 UTC 2012


commit 5fbe32796e265e70aa359d8d540c32e18e59eb9a
Author: Kamil Dudka <kdudka at redhat.com>
Date:   Tue Jan 24 13:25:46 2012 +0100

    reject URLs containing bad data (CVE-2012-0036)

 0012-curl-7.21.3-75ca568.patch |  316 ++++++++++++++++++++++++++++++++++++++++
 curl.spec                      |    8 +-
 2 files changed, 323 insertions(+), 1 deletions(-)
---
diff --git a/0012-curl-7.21.3-75ca568.patch b/0012-curl-7.21.3-75ca568.patch
new file mode 100644
index 0000000..d928513
--- /dev/null
+++ b/0012-curl-7.21.3-75ca568.patch
@@ -0,0 +1,316 @@
+From d86e698610eceb600e83b164cfe94a1498570445 Mon Sep 17 00:00:00 2001
+From: Daniel Stenberg <daniel at haxx.se>
+Date: Fri, 23 Dec 2011 13:24:16 +0100
+Subject: [PATCH] URL sanitize: reject URLs containing bad data
+
+Protocols (IMAP, POP3 and SMTP) that use the path part of a URL in a
+decoded manner now use the new Curl_urldecode() function to reject URLs
+with embedded control codes (anything that is or decodes to a byte value
+less than 32).
+
+URLs containing such codes could easily otherwise be used to do harm and
+allow users to do unintended actions with otherwise innocent tools and
+applications. Like for example using a URL like
+pop3://pop3.example.com/1%0d%0aDELE%201 when the app wants a URL to get
+a mail and instead this would delete one.
+
+This flaw is considered a security vulnerability: CVE-2012-0036
+
+Security advisory at: http://curl.haxx.se/docs/adv_20120124.html
+
+Reported by: Dan Fandrich
+
+Signed-off-by: Kamil Dudka <kdudka at redhat.com>
+---
+ lib/escape.c |  100 ++++++++++++++++++++++++++++++++++-----------------------
+ lib/escape.h |   10 ++++--
+ lib/imap.c   |    7 +---
+ lib/pop3.c   |    6 +---
+ lib/smtp.c   |    7 ++--
+ 5 files changed, 72 insertions(+), 58 deletions(-)
+
+diff --git a/lib/escape.c b/lib/escape.c
+index 735e1d8..0dd5a1d 100644
+--- a/lib/escape.c
++++ b/lib/escape.c
+@@ -5,7 +5,7 @@
+  *                            | (__| |_| |  _ <| |___
+  *                             \___|\___/|_| \_\_____|
+  *
+- * Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel at haxx.se>, et al.
++ * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel at 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
+@@ -24,17 +24,14 @@
+  * allocated string or NULL if an error occurred.  */
+ 
+ #include "setup.h"
+-#include <ctype.h>
++
+ #include <curl/curl.h>
+ 
+-#include <stdio.h>
+-#include <stdlib.h>
+-#include <string.h>
+ #include "curl_memory.h"
+-/* urldata.h and easyif.h are included for Curl_convert_... prototypes */
+ #include "urldata.h"
+-#include "easyif.h"
+ #include "warnless.h"
++#include "non-ascii.h"
++#include "escape.h"
+ 
+ #define _MPRINTF_REPLACE /* use our functions only */
+ #include <curl/mprintf.h>
+@@ -88,13 +85,10 @@ char *curl_easy_escape(CURL *handle, const char *string, int inlength)
+   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;
++  CURLcode res;
+ 
+-#ifndef CURL_DOES_CONVERSIONS
+-  /* avoid compiler warnings */
+-  (void)handle;
+-#endif
+   ns = malloc(alloc);
+   if(!ns)
+     return NULL;
+@@ -103,10 +97,9 @@ char *curl_easy_escape(CURL *handle, const char *string, int inlength)
+   while(length--) {
+     in = *string;
+ 
+-    if (Curl_isunreserved(in)) {
++    if(Curl_isunreserved(in))
+       /* just copy this */
+       ns[strindex++]=in;
+-    }
+     else {
+       /* encode it */
+       newlen += 2; /* the size grows with two, since this'll become a %XX */
+@@ -122,15 +115,12 @@ char *curl_easy_escape(CURL *handle, const char *string, int inlength)
+         }
+       }
+ 
+-#ifdef CURL_DOES_CONVERSIONS
+-/* escape sequences are always in ASCII so convert them on non-ASCII hosts */
+-      if(!handle ||
+-          (Curl_convert_to_network(handle, &in, 1) != CURLE_OK)) {
++      res = Curl_convert_to_network(handle, &in, 1);
++      if(res) {
+         /* Curl_convert_to_network calls failf if unsuccessful */
+         free(ns);
+         return NULL;
+       }
+-#endif /* CURL_DOES_CONVERSIONS */
+ 
+       snprintf(&ns[strindex], 4, "%%%02X", in);
+ 
+@@ -143,26 +133,29 @@ char *curl_easy_escape(CURL *handle, const char *string, int inlength)
+ }
+ 
+ /*
+- * 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;
++  CURLcode res;
+ 
+-#ifndef CURL_DOES_CONVERSIONS
+-  /* avoid compiler warnings */
+-  (void)handle;
+-#endif
+-  if( !ns )
+-    return NULL;
++  if(!ns)
++    return CURLE_OUT_OF_MEMORY;
+ 
+   while(--alloc > 0) {
+     in = *string;
+@@ -178,19 +171,20 @@ char *curl_easy_unescape(CURL *handle, const char *string, int length,
+ 
+       in = curlx_ultouc(hex); /* this long is never bigger than 255 anyway */
+ 
+-#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)) {
++      res = Curl_convert_from_network(data, &in, 1);
++      if(res) {
+         /* 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 +194,33 @@ char *curl_easy_unescape(CURL *handle, const char *string, int length,
+   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 --git a/lib/escape.h b/lib/escape.h
+index 04b06a9..4c7f841 100644
+--- a/lib/escape.h
++++ b/lib/escape.h
+@@ -1,5 +1,5 @@
+-#ifndef __ESCAPE_H
+-#define __ESCAPE_H
++#ifndef HEADER_CURL_ESCAPE_H
++#define HEADER_CURL_ESCAPE_H
+ 
+ /***************************************************************************
+  *                                  _   _ ____  _
+@@ -8,7 +8,7 @@
+  *                            | (__| |_| |  _ <| |___
+  *                             \___|\___/|_| \_\_____|
+  *
+- * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel at haxx.se>, et al.
++ * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel at 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 --git a/lib/imap.c b/lib/imap.c
+index 9c39625..c04ad11 100644
+--- a/lib/imap.c
++++ b/lib/imap.c
+@@ -906,17 +906,12 @@ static CURLcode imap_parse_url_path(struct connectdata *conn)
+   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 --git a/lib/pop3.c b/lib/pop3.c
+index 9f67443..c4699e7 100644
+--- a/lib/pop3.c
++++ b/lib/pop3.c
+@@ -852,11 +852,7 @@ static CURLcode pop3_parse_url_path(struct connectdata *conn)
+   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 --git a/lib/smtp.c b/lib/smtp.c
+index 82621a4..c1ed098 100644
+--- a/lib/smtp.c
++++ b/lib/smtp.c
+@@ -1047,7 +1047,6 @@ static CURLcode smtp_connect(struct connectdata *conn,
+   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 */
+@@ -1121,9 +1120,9 @@ static CURLcode smtp_connect(struct connectdata *conn,
+   }
+ 
+   /* 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
+    */
+-- 
+1.7.1
+
diff --git a/curl.spec b/curl.spec
index 1f7add6..bfc360a 100644
--- a/curl.spec
+++ b/curl.spec
@@ -1,7 +1,7 @@
 Summary: A utility for getting files from remote servers (FTP, HTTP, and others)
 Name: curl
 Version: 7.21.3
-Release: 12%{?dist}
+Release: 13%{?dist}
 License: MIT
 Group: Applications/Internet
 Source: http://curl.haxx.se/download/%{name}-%{version}.tar.lzma
@@ -39,6 +39,9 @@ Patch9: 0009-curl-7.21.3-d6f319f.patch
 # break busy loops in tests 502, 555, and 573
 Patch11: 0011-curl-7.21.1-3445fa2.patch
 
+# reject URLs containing bad data (CVE-2012-0036)
+Patch12: 0012-curl-7.21.7-75ca568.patch
+
 # patch making libcurl multilib ready
 Patch101: 0101-curl-7.21.1-multilib.patch
 
@@ -262,6 +265,9 @@ rm -rf $RPM_BUILD_ROOT
 %{_datadir}/aclocal/libcurl.m4
 
 %changelog
+* Tue Jan 24 2012 Kamil Dudka <kdudka at redhat.com> 7.21.3-13
+- reject URLs containing bad data (CVE-2012-0036)
+
 * Mon Sep 19 2011 Kamil Dudka <kdudka at redhat.com> 7.21.3-12
 - curl-config now provides dummy --static-libs option (#733956)
 - break busy loops in tests 502, 555, and 573


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