Secunia Research: Notepad++ NppFTP "PASV" Buffer Overflow Vulnerabilities

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                     Secunia Research 19/12/2011

      - Notepad++ NppFTP "PASV" Buffer Overflow Vulnerabilities -

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Table of Contents

Affected Software....................................................1
Severity.............................................................2
Vendor's Description of Software.....................................3
Description of Vulnerability.........................................4
Solution.............................................................5
Time Table...........................................................6
Credits..............................................................7
References...........................................................8
About Secunia........................................................9
Verification........................................................10

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1) Affected Software 

* Notepad++ 5.9.6.2	

NOTE: Other versions may also be affected.

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2) Severity 

Rating: Moderately critical
Impact: System access
Where:  From remote

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3) Vendor's Description of Software 

"Notepad++ is a free (as in "free speech" and also as in "free beer")
source code editor and Notepad replacement that supports several
languages. Running in the MS Windows environment, its use is governed
by GPL License.".

Product Link:
http://notepad-plus-plus.org/

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4) Description of Vulnerability

Secunia Research has discovered three vulnerabilities in Notepad++,
which can be exploited by malicious people to compromise a user's 
system.

The vulnerabilities are caused by boundary errors in the 
"CUT_FTPClient::GetDirInfoPASV()", "CUT_FTPClient::ReceiveFilePASV()",
and "CUT_FTPClient::SendFilePASV()" functions (UTCP/source/ftp_c.cpp)
of the NppFTP plugin when parsing "PASV" responses. This can be
exploited to cause stack-based buffer overflows by returning specially
crafted responses to the "PASV" command.

Successful exploitation requires that a user is tricked into 
connecting to a malicious FTP server using the passive mode.

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5) Solution 

Do not connect to untrusted FTP servers.

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6) Time Table 

18/10/2011 - Vendor notified.
02/11/2011 - Vendor notified again.
19/12/2011 - Public disclosure.

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7) Credits 

Discovered by Stefan Cornelius, Secunia Research.

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8) References

The Common Vulnerabilities and Exposures (CVE) project has assigned 
CVE-2011-3843 for the vulnerabilities.

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9) About Secunia

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10) Verification 

Please verify this advisory by visiting the Secunia website:
http://secunia.com/secunia_research/2011-90/

Complete list of vulnerability reports published by Secunia Research:
http://secunia.com/secunia_research/

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