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full-disclosure-uk: [Full-disclosure] [TZO-2009-1] Avira Antivir

[Full-disclosure] [TZO-2009-1] Avira Antivir - RAR - Division by Zero & Null Pointer Dereference

From: Thierry Zoller <Thierry_at_nospam>
Date: Wed Jan 14 2009 - 17:15:49 GMT
To: NTBUGTRAQ <NTBUGTRAQ@LISTSERV.NTBUGTRAQ.COM>, bugtraq <bugtraq@securityfocus.com>, full-disclosure <full-disclosure@lists.grok.org.uk>, <info@circl.etat.lu>, <vuln@secunia.com>, <cert@cert.org>, <nvd@nist.gov>, <cve@mitre.org>

     Avira - RAR -Division by Zero & Null Pointer Dereference

Reference : [TZO-2009-1]-Avira Antivir Location : http://blog.zoller.lu/2009/01/advisory-tzo-2009-1-avira-antivir-rar.html Products : Avira Antivr Free Avira AntiVir Premium Avira Premium Security Suite Avira AntiVir Professional Avira AntiVir for KEN! 4 Avira AntiVir & AntiSpam for KEN! 4 Avira WebProtector for KEN! 4 Avira AntiVir SharePoint Avira AntiVir Virus Scan Adapter for SAP NetWeaver® Avira AntiVir MailGate Avira MailGate Suite Avira AntiVir Exchange Avira AntiVir MIMEsweeper Avira AntiVir Domino Avira AntiVir WebGate Avira WebGate Suite Avira AntiVir ISA Server Avira AntiVir MIMEsweeper Avira AntiVir Mobile Avira SmallBusiness Suite Avira Business Bundle Avira AntiVir NetGate Bundle Avira AntiVir NetWork Bundle Avira AntiVir GateWay Bundle Avira AntiVir Campus (for Education)

Vendors and Products using the Avira Engine : Important : The impact of this flaw on those devices has not been tested nor confirmed to exist, there is however reason to believe that the flaw existed in this products aswell.

http://www.avira.com/documents/utils/pdf/products/pi_system-integration_en.pdf AXIGEN Mail Server Clearswift Mimesweeper GeNUGate and GeNUGate Pro (optional addon) IQ.Suite Vendor : http://www.avira.de

I. Background

Avira is a leading worldwide provider of self-developed protection solutions for professional and private use. The company belongs to the pioneers in this sector with over twenty years experience.

The protection experts have numerous company locations throughout Germany and cultivate partnerships in Europe, Asia and America. Avira has more than 180 employees at their main office in Tettnang near Lake Constance and is one of the largest employers in the region. There are around 250 people employed worldwide whose commitment is continually being confirmed by awards. A significant contribution to protection is the Avira AntiVir Personal which is being used by private users a million times over.

AV-Comparatives e.V. have chosen Avira AntiVir Premium as the best anti-virus solution of 2008

II. Description

By manipulating certain fields inside a RAR archive and attacker might trigger division by zero and null point exceptions. The attack vector should be rated as remote as an attachement to an e-mail is enough.

*Anybody else noticed that the amount of details in most advisories have *become less than usefull ?*

III. Impact

In some cases the impact is a Denial of Service condition in others to an invalid read size of 4 bytes which again in some cases lead to an null pointer dereference.

The RAR parser inside the module leads to various errors whose exploitability index is rated "I don't have time for this now - so let's say 'maybe'" also sometimes known as "I lack the time and/or the skill to do so".

0131cad9 8b10 mov edx,dword ptr [eax] EXCEPTION_RECORD: ffffffff -- (.exr 0xffffffffffffffff) ExceptionAddress: 0131cad9 (aepack!module_get_api+0x00020ed9)

   ExceptionCode: c0000005 (Access violation)    ExceptionFlags: 00000000
NumberParameters: 2

   Parameter[0]: 00000000
   Parameter[1]: 00000268
Attempt to read from address 00000268

OVERLAPPED_MODULE: Address regions for 'AVREP' and 'rcimage.dll' overlap

READ_ADDRESS: 00000268

STACK_TEXT: 0194f5fc 0131cb8c 0115bbfc 00000003 00000100 aepack!module_get_api+0x20ed9 0194f618 01319b96 0115bbfc 074cc4f4 00000002 aepack!module_get_api+0x20f8c 0194f654 0131a45a 00000010 01157160 00000001 aepack!module_get_api+0x1df96 0194f668 0131e7e0 000000d4 00f48ba8 011530d0 aepack!module_get_api+0x1e85a 0194f68c 01318c35 01157160 00000010 011530d0 aepack!module_get_api+0x22be0 00000000 00000000 00000000 00000000 00000000 aepack!module_get_api+0x1d035

0131cad9 8b10 mov edx,dword ptr [eax]

SYMBOL_NAME: aepack!module_get_api+20ed9 MODULE_NAME: aepack
IMAGE_NAME: aepack.dll


IV. Disclosure Timeline

The Vulnerability notification policy i adhere to: http://blog.zoller.lu/search/label/Vulnerability%20disclosure%20Policy  

17/12/2008 : Sent notice to the correct mail adress security@avira. com

17/12/2008 : Avira achknowledges receipt

17/12/2008 : Avira sends details of the root cause on the same day "The crash occurs in a heavily corrupted, generated RAR archive while extracting the contents of the 22nd file. We can't give any file names as they are non-printable characters. "

13/01/2009 : Avira notifies me that the issue was fixed with an update that shipped with AVPack on the 09/01/2009

14/01/2009 : Avira states that all products have been affected except "Securityy Management Center" and the "Internet Update Manager". "Das bedeutet im Prinzip wirklich alle Produkte, ausser Produkte wie eben das Security Management Center oder der Internet Update Manager"

14/01/2009 : Release of this advisory

Thierry Zoller

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