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

This commit is contained in:
Tomas Mraz 2014-03-31 16:22:42 +02:00
parent 0cfc638648
commit 9b30e30268
2 changed files with 62 additions and 1 deletions

View File

@ -0,0 +1,56 @@
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

View File

@ -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@redhat.com> 1.1.8-10
- fix CVE-2014-2583: potential path traversal issue in pam_timestamp
* Wed Mar 26 2014 Tomáš Mráz <tmraz@redhat.com> 1.1.8-9
- pam_pwhistory: call the helper if SELinux enabled