diff -upr cmd5checkpw-0.30.orig/main.c cmd5checkpw-0.30/main.c
--- cmd5checkpw-0.30.orig/main.c	2003-09-18 16:34:01.000000000 +0300
+++ cmd5checkpw-0.30/main.c	2005-07-31 13:19:25.000000000 +0300
@@ -5,6 +5,7 @@
 #include <pwd.h>
 #include <stdio.h>
 #include <unistd.h>
+#include <sys/types.h>
 
 #define LINE_MAX 256
 #define SASLUSERFILE "/var/qmail/users/authuser"
@@ -23,10 +24,26 @@ int doit(unsigned char *testlogin, unsig
    unsigned char h;
    FILE *fp;
    int j;
-
+   uid_t uid;
+   gid_t gid;
    char *linepnt;
 
    if ((fp = fopen(SASLUSERFILE, READONLY)) == NULL) _exit(2);
+
+   uid = getuid();
+   gid = getgid();
+
+   if (gid != getegid()) {
+       if (setegid(gid))
+       _exit(2);
+   }
+
+
+   if (uid && (uid != geteuid())) {
+       if (seteuid(uid))
+       _exit(2);
+   }
+
    while (fgets(line, LINE_MAX, fp) != NULL) {
          if ((linepnt = strchr(line, '\n')) != NULL) {
 	 *linepnt = 0;
@@ -39,7 +56,8 @@ int doit(unsigned char *testlogin, unsig
 	 break;
       }
    }   
-   fclose(fp);
+
+   if (EOF == fclose(fp)) _exit(2);
 
    if (!found_user) return(1);