SEC Consult Vulnerability Lab Security Advisory < 20110810-0 >
title: Client-side remote file upload & command execution
product: Check Point SSL VPN On-Demand applications (signed Java
applet and ActiveX control)
* SSL Network Extender (SNX)
* Endpoint Security On-Demand
supplied by Check Point Connectra or other security
vulnerable version: multiple products, see sections below
fixed version: multiple products, see sections below
CVE number: CVE-2011-1827
by: Johannes Greil / SEC Consult Vulnerability Lab
"SSL Network Extender (SNX) is a browser plug-in that provides clientless
remote access, while delivering full network connectivity for any IP-based
"Comprehensive Endpoint Security
Scans for spyware to ensure that malicious processes, keystroke loggers, and
Trojan horses are not installed on remote endpoints, Connectra scans for these
and other spyware through remote users’ browsers. By disabling spyware and
enforcing baseline security requirements before it grants SSL VPN access,
Connectra stops identity and password theft and prevents data loss."
The client-side endpoint security solution (SSL Network Extender (SNX),
SecureWorkSpace and Endpoint Security On-Demand), e.g. supplied by a Check
Point Connectra or other Check Point security appliances on the portal page,
uses either a signed Java applet (called CShell or Deployment Agent) or
ActiveX control to perform local compliance scans on the client.
Due to quality issues within the software, an attacker is able to access
insecure methods from the "trustworthy" Java applet or ActiveX control and
exploit those features to compromise all client systems that trust the
correctly signed Java applet or ActiveX control (e.g. all users that need to
use this software for accessing internal systems over company VPN).
As SEC Consult does not provide free of charge quality assurance for software
vendors above providing information in advisories, no further proof of
concepts than this advisory / exploit have been created.
The Check Point Deployment agent Java applet or ActiveX control have a "Secure
Workspace" (SWS) feature which is provided per default in "sws.jar" (or
"sws.cab"). This JAR-file is extracted to %TEMP%\SWS (Windows) or /tmp/SWS
(Linux). It includes the executable CPSWS.exe and some other XML and DLL files
(side note: it is no workaround to remove "sws.jar" on the company Check Point
Connectra appliance as this file can also remotely be deployed or fetched).
Calling the public method "CreatePackageURL" it is possible for an attacker to
load the SWS feature/package. Afterwards "RunPackageAction" can be called to
access the following actions of the "Secure Workspace" component:
The proof of concept uses "dwnldFile" and "runCmd" to upload an arbitrary
executable file and store it as "CPSWS.exe" within the temporary directory of
the victim's client system. Then "runCmd" is being called to automatically run
the new malicious "CPSWS.exe" and compromise the client system.
So it's not just possible to execute commands on the clients but also to
choose one's own arbitrary malicious payload.
Summing up, an attacker is able to upload arbitrary executable files to remote
clients and then immediately execute them without notice as a signed Java
applet / ActiveX is being used (if "Always trust content from this publisher"
has been checked - otherwise an unsuspicious Java digital signature
verification popup will occur).
Possible attack vectors are drive-by downloads just by visiting malicious
websites but also through emails, any XSS on unsuspicous websites, etc.
Proof of concept:
The exploit will not be published, but a video demonstrating this issue has
been created. It can be found at the following URL:
Vulnerable / tested versions:
The Deployment agent component of the Check Point Connectra R66 appliance has
been tested and successfully exploited. Furthermore, a newer R70 has also been
tested and found vulnerable.
Vulnerable signed Java applet certificate SHA1 fingerprint:
Vulnerable ActiveX control "SlimClient Class" Class ID:
Further information regarding affected Class ID and Oracle Java Blacklist SHA1-Hashes
can be found within the advisory of Check Point.
The following affected product/version information has been supplied by Check
- Connectra R66.1
- Connectra R66.1n
- VSX R65.20
- VSX R67
Vendor contact timeline:
2011-03-31: Contacting Check Point security team
(email@example.com), received auto-reply email
2011-03-31: Vendor: Very fast response, issue is being investigated, Check
Point will reply early next week
2011-04-03: Vendor: asking for further information, exploit setup
2011-04-04: Replying to vendor
2011-04-05: Vendor: confirmation of vulnerability, more information
end of week
2011-04-08: Asking for status
2011-04-09: Vendor: Working on the fix and release plan
2011-04-11: Asking for CVE number @MITRE
2011-04-12: Sending more details to MITRE, asking Check Point for version
numbers and affected products
2011-04-13 - 2011-04-22: Coordination with Check Point regarding release and
2011-04-21: Contacting local CERT (Austria, Germany)
2011-04-25: Check Point releases their advisory including patches
2011-04-26: Asking again for CVE number
2011-05-26: Asking about status for Microsoft killbit patch
2011-05-29: Vendor: Microsoft did postpone patch from June to August
2011-08-08: Asking about status for patch; Vendor: MS publication expected
2011-08-09: Microsoft publishes killbit patch
2011-08-10: Coordinated release of SEC Consult advisory
The following patches have been supplied by Check Point:
- Hotfix for R65.70
- Hotfix for R70.40
- Hotfix for R71.30
- Hotfix for R75
- Hotfix for Connectra R66.1
- Hotfix for Connectra R66.1n
- Hotfix for VSX R65.20
- Hotfix for VSX R67
For further information see the advisory of Check Point:
The following Microsoft Killbit Patch should be applied:
You should really apply the patches and invalidate the vulnerable ActiveX
control and Java applet.
Detailed information and a howto including tools can be found within the
advisory of Check Point.
SEC Consult Unternehmensberatung GmbH
Tel.: +43 / 1 / 890 30 43 - 0
Fax.: +43 / 1 / 890 30 43 - 25
Mail: research at sec-consult dot com
EOF J. Greil / @2011