UnRAR-DLL Plugin - has a critical security bug

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Posts: 2
Joined: 27 Aug 2023, 20:56

UnRAR-DLL Plugin - has a critical security bug

Post by Sam »


I do promotion for Servant Salamander (at least) since I knew it from version 1.54.

Recently WinRAR had a vulnerability bug which could execute malicious code even when opening a prepared rar file, which contains recovrey volume information.
https://www.heise.de/news/WinRAR-Luecke ... 83622.html

Years ago, WinACE plugins were a security problem in several programs as they enabled opening prepared ace-files (7zip, winrar, winzip, peazip, Total Commander .... and much more more)

Now, it's Winrar.
And several offering rar-handling programs are affected.

So I instantly downloaded unrar.dll from winrar homepage and tried to exchang it in all occurencies on my systems.
But when I now click on rar archives, I get a message that Servant cannot load the unrar.dll library, because wouldn't be a Win32 application.
"Unrar-Plugin unrar.spl is no Servant plugin or has an internal error"

However when I examine the (old;your) unrar.dll, I have the suspicion that it does not have a PE 32 format, itself. (self compiled ?)
Even your old dll is bigger than the newer one, directly loaded from winrar (precompiled).

unrar.dll which is comming with Servant 4.0
01.08.2023 11:27 -- Size: 291.928 UnRAR.dll <<<- new one, loaded form winrar
24.06.2019 22:50 -- Size: 320.728 _unrar.dll <<<-- yours
01.07.2019 10:19 -- Size: 65.864 unrar.spl

Although you sorrowly regrettably did not implement Tabs since 2012 (a killer feature!!!),
you should anyhow offer an update for that winrar plugin, because this could lead to a really big security problem for users.
And this would be not worthy for this, absolute fine program, brought us by you.

I hope you can fix it.
(and implement tabs and much more :P)

MANY thanks! (and hope you are well !)

Kind regards.
Posts: 32
Joined: 28 Apr 2006, 16:09
Location: Germany

Re: UnRAR-DLL Plugin - has a critical security bug

Post by knick »

Hi Sam,

I assume you have a 64 Bit installation of Altap Salamander and you've put the 32 Bit UnRAR.dll in the plugin folder. That doesn't work. You have to use the file "UnRAR64.dll" (which is 346.200 Bytes on my system, Version 6.23.0), put it in the plugin folder and rename it to "unrar.dll".

I've tried just a few minutes ago and it worked...

Thank you very much for giving us a hint that the unrar plugin of Salamander is vulnerable. Just yesterday I thought it would be a good idea to make Salamander available (as an installer!) that contains the updated dbviewer plugin *AND* to make Salamander installable with winget (which is nearly a piece of cake)....

Maybe I'll spend some time building a new installer with the dbviewer update AND the unrar update and make it available on GitHub... Maybe on the next rainy day ;-)

Posts: 667
Joined: 14 Dec 2006, 06:22

Re: UnRAR-DLL Plugin - has a critical security bug

Post by therube »

(Existing thread [on the cz end], Děravý WinRAR plugin?.)
WinXP Pro SP3 or Win7 x86 | SS 2.54
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