exploit the possibilities

F-SECURE Generic Malformed Container Bypass

F-SECURE Generic Malformed Container Bypass
Posted Feb 14, 2020
Authored by Thierry Zoller

The F-SECURE parsing engine supports the RAR Archive. The parsing engine can be bypassed by specifically manipulating a RAR archive. Various products are affected.

tags | advisory
MD5 | 192bc50776f25bf49730d36c48892734

F-SECURE Generic Malformed Container Bypass

Change Mirror Download
________________________________________________________________________

From the low-hanging-fruit-department
F-SECURE Generic Malformed Container bypass (RAR)
________________________________________________________________________

Ref : [TZO-15-2020] - F-SECURE Generic Malformed Container
bypass (RAR)
Vendor : F-SECURE
Status : Patched
CVE : none provided
Blog :
https://blog.zoller.lu/p/tzo-15-2020-f-secure-generic-malformed.html
Vulnerability Dislosure Policy: https://caravelahq.com/b/policy/20949

Affected Products
=================
F-Secure Email and Server Security
F-Secure Internet GateKeeper
F-SECURE CLOUD PROTECTION FOR SALESFORCE

Linux below 17.0.605.474

I. Background
----------------------------
Quote: "Unprecedented challenges threaten to undermine the very survival
of society. Only unprecedented innovation can prevent irreversible
disasters. This is only possible if we trust the technology that can
bring us together.

From our humble beginnings more than thirty years ago, F-Secure has
grown into a reliable cyber security leader, earning the trust of
organizations and people around the world."

II. Description
----------------------------
The parsing engine supports the RAR Archive. The parsing engine can be
bypassed by specifically manipulating a RAR archive.


III. Impact
----------------------------
Impacts depends on the contextual use of the product and engine within
the organisation of a customer. Gateway Products (Email, HTTP Proxy etc)
may allow the file through unscanned
and give it a clean bill of health. Server side AV software will not be
able to discover any code or sample contained within this ISO file and
it will not raise suspicion even if you know exactly what you are
looking for (Which is for example great to hide your implants
or Exfiltration/Pivot Server).

There is a lot more to be said about this bug class, so rather than bore
you with it in
this advisory I provide a link to my 2009 blog post
http://blog.zoller.lu/2009/04/case-for-av-bypassesevasions.html

IV. Patch / Advisory
----------------------------
- For the unix version (IGK) the fix was released on 20th January with
library version 17.0.605.474
- For Windows the version was already out in December 2019. There were
also avira's fixes as well.

"We can conclude that January 20th date, since that is when the final
fixes went out to production."

V. Disclosure timeline
----------------------------

NOV 20 2019 - Report
DEC 20 2019 - Windows fixes released
JAN 20 2010 - Linux fix relesased

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

April 2020

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Apr 1st
    60 Files
  • 2
    Apr 2nd
    20 Files
  • 3
    Apr 3rd
    10 Files
  • 4
    Apr 4th
    0 Files
  • 5
    Apr 5th
    0 Files
  • 6
    Apr 6th
    0 Files
  • 7
    Apr 7th
    0 Files
  • 8
    Apr 8th
    0 Files
  • 9
    Apr 9th
    0 Files
  • 10
    Apr 10th
    0 Files
  • 11
    Apr 11th
    0 Files
  • 12
    Apr 12th
    0 Files
  • 13
    Apr 13th
    0 Files
  • 14
    Apr 14th
    0 Files
  • 15
    Apr 15th
    0 Files
  • 16
    Apr 16th
    0 Files
  • 17
    Apr 17th
    0 Files
  • 18
    Apr 18th
    0 Files
  • 19
    Apr 19th
    0 Files
  • 20
    Apr 20th
    0 Files
  • 21
    Apr 21st
    0 Files
  • 22
    Apr 22nd
    0 Files
  • 23
    Apr 23rd
    0 Files
  • 24
    Apr 24th
    0 Files
  • 25
    Apr 25th
    0 Files
  • 26
    Apr 26th
    0 Files
  • 27
    Apr 27th
    0 Files
  • 28
    Apr 28th
    0 Files
  • 29
    Apr 29th
    0 Files
  • 30
    Apr 30th
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2016 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close