RE: WinRAR SFX v5.21 - Remote Code Execution Vulnerability

["Popovici, Alejo \(LATCO - Buenos Aires\)" <apopovici@xxxxxxxxxxxx>]

Well it's true what you are saying,
But it's also true that anti-virus software is fully aware of the usual way of 
executing malicious code through SFX archives. This could be a way of bypassing 
the anti-virus software thus avoiding detection.
In my opinion it should be fixed.

Kind regards,

Alejo Popovici
Consultor | ERS | Cyber Risk Services
Deloitte & Co. S.A.
Pte. Gral.J.D.Perón 646, 7piso, C1038AAN, Buenos Aires Argentina
apopovici@xxxxxxxxxxxx | www.deloitte.com


-----Original Message-----
From: dev@xxxxxxxxxx [mailto:dev@xxxxxxxxxx] 
Sent: Wednesday, September 30, 2015 8:05 AM
To: bugtraq@xxxxxxxxxxxxxxxxx
Subject: Re: WinRAR SFX v5.21 - Remote Code Execution Vulnerability

I am WinRAR developer. We published the official comment on www.rarlab.com here:
http://rarlab.com/vuln_sfx_html.htm

This "vulnerability" is a non-issue. Why attempting to find some hackish 
esoteric way for a feature, which presents in SFX archives officially. Any SFX 
archive can run contained executable files, it is required for installers. Any 
SFX archive just like any exe file and any software installer is potentially 
dangerous for user computers and must be started only if received from a 
trustworthy source.

Self-extracting archives are .exe themselves, one of their basic functions is 
code execution for executables stored in archives. They also allow to run any 
kind of web downloaders, because it is needed for software installers. So that 
researcher discovered that self-extracting archives, which are exe themselves 
and designed to be able to run contained exe, can actually run exe. No surprise 
here and no new risks for users. All associated risks are already present in 
standard SFX functions and exe design.

 
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