1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
/*
** generic wrapper that will take info from a environment
** variable, and pass it to two commands.
**
** 10-17-96 : Hal Schechner
** 12-14-96 : John Viega -- changed to work on 1 command,
** take a list of valid commands,
** just pass on argv, and use execvp()
** Also threw in some useful feedback for when there's
** a failure, mainly for future debugging.
**
** Chmod this bitch 4755.
**
*/
#include <stdio.h>
const char *COMMAND = "/home/mailman/mailman/cgi/listinfo";
/* Might want to make this full path.
I can write whatever program named sendmail,
so this isn't much for security.
*/
const char *LEGAL_PARENT_NAMES[] = {
"httpd",
NULL /* Sentinal, don't remove */
};
/* Should make these arrays too... */
const int LEGAL_PARENT_UID = 60001; /* nobody's UID */
const int LEGAL_PARENT_GID = 60001; /* nobody's GID */
/*
** what is the name of the process with pid of 'pid'
*/
char *get_process_name(int pid) {
FILE *proc;
char fname[30];
char tmp[255];
static char procname[255];
sprintf(fname, "/proc/%d/status", pid);
proc = fopen(fname, "r");
fgets(tmp, 256, proc);
sscanf(tmp, "Name: %s\n", procname);
fclose(proc);
return procname;
}
int valid_parent(char *parent){
int i = 0;
while(LEGAL_PARENT_NAMES[i] != NULL)
{
if(!strcmp(parent, LEGAL_PARENT_NAMES[i]))
{
return 1;
}
i++;
}
return 0;
}
/*
** is the parent process allowed to call us?
*/
int legal_caller() {
/* compare to our parent's uid */
if(LEGAL_PARENT_UID != getuid())
{
printf("GOT UID %d.\n", getuid());
return 0;
}
if(LEGAL_PARENT_GID != getgid())
{
printf("GOT GID %d.\n", getgid());
return 0;
}
return 1;
}
void main(int argc, char **argv, char **env) {
char *command;
int i;
command = (char *)malloc(sizeof(char) * i);
if(legal_caller()) {
argv[0] = (char *)COMMAND;
execve(COMMAND, argv, env);
}
else {
printf("Illegal caller!\n");
}
}
|
