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HP ToComMsg DLL side loading vulnerability
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Yorick Koster, September 2015

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Abstract
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A DLL side loading vulnerability was found in the HP ToComMsg DLL. This
issue can be exploited by loading the TcComMsg.AutoTcComMsg object as an
embedded OLE object. When instantiating the object Windows will try to
load the DLL MFC80ENU.DLL from the current working directory. If an
attacker convinces the user to open a specially crafted (Office)
document from a directory also containing the attacker's DLL file, it is
possible to execute arbitrary code with the privileges of the target
user. This can potentially result in the attacker taking complete
control of the affected system.

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Tested versions
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This issue was successfully verified on the HP Color LaserJet CM2320 MFP
drivers version 3.1 (CM2320series-win7-full-solution-AM-EMEA1-v3.1.exe).

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Fix
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There is currently no fix available, HP reports: "Unfortunately, the
driver software for these devices can no longer be updated. The devices
have ended support life and the engineering resources are no longer
available to provide any firmware updates.  We do understand the issue,
and current drivers are no longer vulnerable to the OLE side load
issue".

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Details
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https://www.securify.nl/advisory/SFY20150902/hp_tocommsg_dll_side_loading_vulnerability.html
https://www.securify.nl/exploit/SFY20150901/hp_laserjet_ole_sideload.html
https://www.securify.nl/blog/SFY20151201/there_s_a_party_in_ole__and_you_are_invited.html