Index: auth/pam.c
===================================================================
RCS file: /cvs/sudo/auth/pam.c,v
retrieving revision 1.51
diff -u -r1.51 pam.c
--- auth/pam.c	25 Jun 2005 18:29:17 -0000	1.51
+++ auth/pam.c	28 Sep 2006 21:47:00 -0000
@@ -249,7 +249,12 @@
 		    p = pm->msg;
 		/* Read the password. */
 		pass = tgetpass(p, def_passwd_timeout * 60, flags);
-		pr->resp = estrdup(pass ? pass : "");
+		if (pass == NULL) {
+		    /* We got ^C instead of a password; abort quickly. */
+		    nil_pw = 1;
+		    return PAM_CONV_ERR;
+		}
+		pr->resp = estrdup(pass);
 		if (*pr->resp == '\0')
 		    nil_pw = 1;		/* empty password */
 		else