diff -up mod_auth_shadow-2.2/mod_auth_shadow.c.CVE-2010-1151 mod_auth_shadow-2.2/mod_auth_shadow.c
--- mod_auth_shadow-2.2/mod_auth_shadow.c.CVE-2010-1151	2007-04-02 17:38:27.000000000 +0200
+++ mod_auth_shadow-2.2/mod_auth_shadow.c	2010-04-09 14:26:05.949633122 +0200
@@ -144,6 +144,7 @@ static int auth_shadow_authorize(const c
     int filedes[2];  /* fd's for pipe.  Read from 0, write to 1*/
     char validate_prog[255];
     int ret, status;
+    int cpid;
     FILE* fp;
 
     if (strlen(INSTBINDIR) > 240) {
@@ -192,6 +193,9 @@ static int auth_shadow_authorize(const c
 
     /* Parent */
 
+    /* Save child pid - we must only accept answers from it */
+    cpid = ret;
+
     /* We write to the pipe, then wait for the child to finish. */
     fp = fdopen(filedes[1],"w");
     if (!fp) {
@@ -209,12 +213,17 @@ static int auth_shadow_authorize(const c
         return(-1);
     }
 
-    ret = wait(&status);
-    if (ret==0 || ret==-1) {
+    ret = waitpid(cpid, &status, 0);
+    if (ret==-1) {
         ap_log_error(APLOG_MARK, APLOG_EMERG, errno, r->server,
         "%s: Error while waiting for child: %d.",module_name, errno);
         return(-1);
     }
+    if (ret==0 || ret!=cpid) {
+        ap_log_error(APLOG_MARK, APLOG_EMERG, errno, r->server,
+        "%s: Failure waiting for child (none or wrong child returned): %d.",module_name, ret);
+        return(-1);
+    }
 
     if (status==0)
         return 1;  /* Correct pw */
@@ -307,7 +316,7 @@ static int user_in_group (char *user, co
     }
 
     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
-       "%s: Looking in group file for %d: got user: %s", module_name, 
+       "%s: Looking in group file for %s: got user: %s", module_name, 
 		groupname, user);
 
     // Get group information from group file using re-entrant