- fixed postfix privilege problem with symlinks in the mail spool directory

(CVE-2008-2936) (rhbz#459101)
This commit is contained in:
Thomas Woerner 2008-08-14 14:06:44 +00:00
parent 63c5c3f41c
commit afa06e5b2e
2 changed files with 66 additions and 1 deletions

View File

@ -0,0 +1,59 @@
*** postfix/src/util/safe_open.c.orig Sun Jun 4 19:04:49 2006
- --- postfix/src/util/safe_open.c Mon Aug 4 16:47:18 2008
***************
*** 83,88 ****
- --- 83,89 ----
#include <msg.h>
#include <vstream.h>
#include <vstring.h>
+ #include <stringops.h>
#include <safe_open.h>
/* safe_open_exist - open existing file */
***************
*** 138,150 ****
* for symlinks owned by root. NEVER, NEVER, make exceptions for symlinks
* owned by a non-root user. This would open a security hole when
* delivering mail to a world-writable mailbox directory.
*/
else if (lstat(path, &lstat_st) < 0) {
vstring_sprintf(why, "file status changed unexpectedly: %m");
errno = EPERM;
} else if (S_ISLNK(lstat_st.st_mode)) {
! if (lstat_st.st_uid == 0)
! return (fp);
vstring_sprintf(why, "file is a symbolic link");
errno = EPERM;
} else if (fstat_st->st_dev != lstat_st.st_dev
- --- 139,167 ----
* for symlinks owned by root. NEVER, NEVER, make exceptions for symlinks
* owned by a non-root user. This would open a security hole when
* delivering mail to a world-writable mailbox directory.
+ *
+ * Sebastian Krahmer of SuSE brought to my attention that some systems have
+ * changed their semantics of link(symlink, newpath), such that the
+ * result is a hardlink to the symlink. For this reason, we now also
+ * require that the symlink's parent directory is writable only by root.
*/
else if (lstat(path, &lstat_st) < 0) {
vstring_sprintf(why, "file status changed unexpectedly: %m");
errno = EPERM;
} else if (S_ISLNK(lstat_st.st_mode)) {
! if (lstat_st.st_uid == 0) {
! VSTRING *parent_buf = vstring_alloc(100);
! const char *parent_path = sane_dirname(parent_buf, path);
! struct stat parent_st;
! int parent_ok;
!
! parent_ok = (stat(parent_path, &parent_st) == 0 /* not lstat */
! && parent_st.st_uid == 0
! && (parent_st.st_mode & (S_IWGRP | S_IWOTH)) == 0);
! vstring_free(parent_buf);
! if (parent_ok)
! return (fp);
! }
vstring_sprintf(why, "file is a symbolic link");
errno = EPERM;
} else if (fstat_st->st_dev != lstat_st.st_dev

View File

@ -40,7 +40,7 @@
Name: postfix
Summary: Postfix Mail Transport Agent
Version: 2.5.1
Release: 2%{?dist}
Release: 3%{?dist}
Epoch: 2
Group: System Environment/Daemons
URL: http://www.postfix.org
@ -81,6 +81,7 @@ Patch7: postfix-2.1.5-aliases.patch
Patch8: postfix-large-fs.patch
Patch9: postfix-2.4.0-cyrus.patch
Patch10: postfix-2.4.5-open_define.patch
Patch11: postfix-CVE-2008-2936.patch
# Optional patches - set the appropriate environment variables to include
# them when building the package/spec file
@ -139,6 +140,7 @@ TLS
%patch8 -p1 -b .large-fs
%patch9 -p1 -b .cyrus
%patch10 -p1 -b .open_define
%patch11 -p1 -b .CVE-2008-2936
# resolve multilib conflict for makedefs.out: rename to makedefs.out-%{_arch}
perl -pi -e "s/makedefs.out/makedefs.out-%{_arch}/g" conf/postfix-files Makefile.in */Makefile.in */*/Makefile.in HISTORY
@ -480,6 +482,10 @@ exit 0
%changelog
* Thu Aug 14 2008 Thomas Woerner <twoerner@redhat.com> 2:2.5.1-3
- fixed postfix privilege problem with symlinks in the mail spool directory
(CVE-2008-2936) (rhbz#459101)
* Wed Mar 12 2008 Thomas Woerner <twoerner@redhat.com> 2:2.5.1-2
- fixed fix for enabling IPv6 support (rhbz#437024)
- added new postfix data directory (rhbz#437042)