[pam] fix CVE-2014-2583: potential path traversal issue in pam_timestamp

[Tomáš Mráz]

commit 9b30e3026854b9486be944cd587517b423cd102e
Author: Tomas Mraz <tmraz at fedoraproject.org>
Date:   Mon Mar 31 16:22:42 2014 +0200

    fix CVE-2014-2583: potential path traversal issue in pam_timestamp

 pam-1.1.8-cve-2014-2583.patch |   56 +++++++++++++++++++++++++++++++++++++++++
 pam.spec                      |    7 ++++-
 2 files changed, 62 insertions(+), 1 deletions(-)
---
diff --git a/pam-1.1.8-cve-2014-2583.patch b/pam-1.1.8-cve-2014-2583.patch
new file mode 100644
index 0000000..f2aa2de
--- /dev/null
+++ b/pam-1.1.8-cve-2014-2583.patch
@@ -0,0 +1,56 @@
+From 9dcead87e6d7f66d34e7a56d11a30daca367dffb Mon Sep 17 00:00:00 2001
+From: "Dmitry V. Levin" <ldv at 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 at 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
+
diff --git a/pam.spec b/pam.spec
index 9b716cc..930e340 100644
--- a/pam.spec
+++ b/pam.spec
@@ -3,7 +3,7 @@
 Summary: An extensible library which provides authentication for applications
 Name: pam
 Version: 1.1.8
-Release: 9%{?dist}
+Release: 10%{?dist}
 # The library is BSD licensed with option to relicense as GPLv2+
 # - this option is redundant as the BSD license allows that anyway.
 # pam_timestamp, pam_loginuid, and pam_console modules are GPLv2+.
@@ -46,6 +46,7 @@ Patch32: pam-1.1.7-tty-audit-init.patch
 Patch33: pam-1.1.8-translation-updates.patch
 Patch34: pam-1.1.8-canonicalize-username.patch
 Patch35: pam-1.1.8-cve-2013-7041.patch
+Patch36: pam-1.1.8-cve-2014-2583.patch
 
 %define _pamlibdir %{_libdir}
 %define _moduledir %{_libdir}/security
@@ -125,6 +126,7 @@ mv pam-redhat-%{pam_redhat_version}/* modules
 %patch33 -p2 -b .translations
 %patch34 -p1 -b .canonicalize
 %patch35 -p1 -b .case
+%patch36 -p1 -b .timestamp-ruser
 
 %build
 autoreconf -i
@@ -373,6 +375,9 @@ fi
 %doc doc/adg/*.txt doc/adg/html
 
 %changelog
+* Mon Mar 31 2014 Tomáš Mráz <tmraz at redhat.com> 1.1.8-10
+- fix CVE-2014-2583: potential path traversal issue in pam_timestamp
+
 * Wed Mar 26 2014 Tomáš Mráz <tmraz at redhat.com> 1.1.8-9
 - pam_pwhistory: call the helper if SELinux enabled