1 From 9dcead87e6d7f66d34e7a56d11a30daca367dffb Mon Sep 17 00:00:00 2001
2 From: "Dmitry V. Levin" <ldv@altlinux.org>
3 Date: Wed, 26 Mar 2014 22:17:23 +0000
4 Subject: pam_timestamp: fix potential directory traversal issue (ticket #27)
6 pam_timestamp uses values of PAM_RUSER and PAM_TTY as components of
7 the timestamp pathname it creates, so extra care should be taken to
8 avoid potential directory traversal issues.
10 * modules/pam_timestamp/pam_timestamp.c (check_tty): Treat
11 "." and ".." tty values as invalid.
12 (get_ruser): Treat "." and ".." ruser values, as well as any ruser
13 value containing '/', as invalid.
17 Reported-by: Sebastian Krahmer <krahmer@suse.de>
18 Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
20 diff --git a/modules/pam_timestamp/pam_timestamp.c b/modules/pam_timestamp/pam_timestamp.c
21 index 5193733..b3f08b1 100644
22 --- a/modules/pam_timestamp/pam_timestamp.c
23 +++ b/modules/pam_timestamp/pam_timestamp.c
24 @@ -158,7 +158,7 @@ check_tty(const char *tty)
25 tty = strrchr(tty, '/') + 1;
27 /* Make sure the tty wasn't actually a directory (no basename). */
28 - if (strlen(tty) == 0) {
29 + if (!strlen(tty) || !strcmp(tty, ".") || !strcmp(tty, "..")) {
33 @@ -243,6 +243,17 @@ get_ruser(pam_handle_t *pamh, char *ruserbuf, size_t ruserbuflen)
39 + * This ruser is used by format_timestamp_name as a component
40 + * of constructed timestamp pathname, so ".", "..", and '/'
41 + * are disallowed to avoid potential path traversal issues.
43 + if (!strcmp(ruser, ".") ||
44 + !strcmp(ruser, "..") ||
45 + strchr(ruser, '/')) {
49 if (ruser == NULL || strlen(ruser) >= ruserbuflen) {