Original Release Date: 2007-02-23 | Last Revised: 2009-04-13
The SupportSoft ActiveX controls contain multiple buffer overflow vulnerabilities, which could allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.
SupportSoft provides multiple ActiveX packages that are used by third party vendors to provide remote assistance and other technical support functions. The controls are commonly used by internet service providers (ISPs) and PC manufacturers. The SupportSoft ActiveX control packages contain multiple buffer overflow vulnerabilities. Many of these buffer overflows can be used to overwrite the process Structured Exception Handler (SEH) or otherwise overwrite the contents of the EIP (Extended Instruction Pointer) register, thus gaining control of program execution flow.
According to the SupportSoft ActiveX Controls Security Update, one should search for any of the following files to determine if a system may be vulnerable: tgctlsi.dll tgctlins.dll sdcnetcheck.dll tgctlar.dll tgctlch.dll tgctlpr.dll tgctlcm.dll tglib.dll tgctlidx.dll Note that since the vulnerable controls are commonly included with third-party software that is not explicitly packaged as "SupportSoft," searching for the above files is the most effective way to determine if a system is vulnerable.
By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), an attacker may be able to execute arbitrary code with the privileges of the user. The attacker could also cause Internet Explorer (or the program using the WebBrowser control) to crash.
Apply an update Please check with your vendor for an update specific to your vendor's product.
Symantec customers should apply an update, as specified by Symantec advisory SYM07-002.
For customers where the vendor has not supplied an update, please apply an update as specified in the SupportSoft Security Update. This update provides download links to installers for the fixed 6.5.x and 5.6.x controls. Please note that a computer system may have both 6.x and 5.x components installed, which would require installing both update packages.
Disable vulnerable SupportSoft ActiveX controls in Internet Explorer
Vulnerable SupportSoft ActiveX controls can be disabled in Internet Explorer by setting the kill bit for the following CLSIDs:
More information about how to set the kill bit is available in Microsoft Support Document 240797. Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for these controls:
Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.