- Fix CVE-2014-2583: pam_timestamp path injection (bnc#870433)

bug-870433_pam_timestamp-fix-directory-traversal.patch

OBS-URL: https://build.opensuse.org/package/show/Linux-PAM/pam?expand=0&rev=139

bug-870433_pam_timestamp-fix-directory-traversal.patch

@@ -0,0 +1,53 @@
+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';

pam.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Wed Apr  9 16:02:17 UTC 2014 - ckornacker@suse.com
+
+- Fix CVE-2014-2583: pam_timestamp path injection (bnc#870433)
+  bug-870433_pam_timestamp-fix-directory-traversal.patch
+
 -------------------------------------------------------------------
 Tue Apr  1 15:35:56 UTC 2014 - ckornacker@suse.com
 

pam.spec

@@ -55,6 +55,7 @@ Patch0:         fix-man-links.dif
 Patch1:         Linux-PAM-git-20140127.diff
 Patch2:         pam_loginuid-log_write_errors.diff
 Patch3:         pam_xauth-sigpipe.diff
+Patch4:         bug-870433_pam_timestamp-fix-directory-traversal.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 
 %description
@@ -102,6 +103,7 @@ building both PAM-aware applications and modules for use with PAM.
 %patch1 -p2
 %patch2 -p1
 %patch3 -p1
+%patch4 -p1
 
 %build
 export CFLAGS="%optflags -DNDEBUG"