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- From 9dcead87e6d7f66d34e7a56d11a30daca367dffb Mon Sep 17 00:00:00 2001
- From: "Dmitry V. Levin" <ldv@altlinux.org>
- Date: Wed, 26 Mar 2014 22:17:23 +0000
- Subject: [PATCH] pam_timestamp: fix potential directory traversal issue
- (ticket #27)
- pam_timestamp uses values of PAM_RUSER and PAM_TTY as components of
- the timestamp pathname it creates, so extra care should be taken to
- avoid potential directory traversal issues.
- * modules/pam_timestamp/pam_timestamp.c (check_tty): Treat
- "." and ".." tty values as invalid.
- (get_ruser): Treat "." and ".." ruser values, as well as any ruser
- value containing '/', as invalid.
- Fixes CVE-2014-2583.
- Reported-by: Sebastian Krahmer <krahmer@suse.de>
- ---
- modules/pam_timestamp/pam_timestamp.c | 13 ++++++++++++-
- 1 file changed, 12 insertions(+), 1 deletion(-)
- diff --git a/modules/pam_timestamp/pam_timestamp.c b/modules/pam_timestamp/pam_timestamp.c
- index 5193733..b3f08b1 100644
- --- a/modules/pam_timestamp/pam_timestamp.c
- +++ b/modules/pam_timestamp/pam_timestamp.c
- @@ -158,7 +158,7 @@ check_tty(const char *tty)
- tty = strrchr(tty, '/') + 1;
- }
- /* Make sure the tty wasn't actually a directory (no basename). */
- - if (strlen(tty) == 0) {
- + if (!strlen(tty) || !strcmp(tty, ".") || !strcmp(tty, "..")) {
- return NULL;
- }
- return tty;
- @@ -243,6 +243,17 @@ get_ruser(pam_handle_t *pamh, char *ruserbuf, size_t ruserbuflen)
- if (pwd != NULL) {
- ruser = pwd->pw_name;
- }
- + } else {
- + /*
- + * This ruser is used by format_timestamp_name as a component
- + * of constructed timestamp pathname, so ".", "..", and '/'
- + * are disallowed to avoid potential path traversal issues.
- + */
- + if (!strcmp(ruser, ".") ||
- + !strcmp(ruser, "..") ||
- + strchr(ruser, '/')) {
- + ruser = NULL;
- + }
- }
- if (ruser == NULL || strlen(ruser) >= ruserbuflen) {
- *ruserbuf = '\0';
- --
- 1.8.3.1
|
