April 17, 2008
Microsoft Works 7 'WkImgSrv.dll' ActiveX control is prone to a remote code-execution vulnerability because it fails to sufficiently verify user-supplied input. An attacker can exploit this issue to run arbitrary attacker-supplied code in the context of the currently logged-in user. Failed exploits attempts will trigger denial-of-service conditions. This issue affects Microsoft Works 7 'WkImgSrv.dll' ActiveX control 7.03.0616; other versions may also be vulnerable. NOTE: This ActiveX control is not marked 'safe for scripting' and would therefore prompt the victim before executing the script. Typically, we would not classify this issue as a security vulnerability. However, given the nature of the issue and the existence of exploit code in the wild, this BID will not be retired so that a record of the issue can be maintained.
- Microsoft WkImgSrv.dll 7.03.0616
Block external access at the network boundary, unless external parties require service.
If global access isn't needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of successful exploits.
Run all software as a nonprivileged user with minimal access rights.
To limit the potential damage that a successful exploit may achieve, run all nonadministrative software as a regular user with the least amount of privileges required to successfully operate.
Do not follow links provided by unknown or untrusted sources.
Do not following links, visit websites, or open files that originate from untrusted sources.
Set web browser security to disable the execution of script code or active content.
Since exploiting this issue requires malicious script code to run in web clients, consider disabling support for script code and active content within the client browser. Note that this mitigation tactic might adversely affect websites that rely on the execution of browser-based script code.
Review and adjust according to policy any default configuration settings.
To mitigate the possibility of exploiting this issue through HTML email, configure email clients to render messages as text only. Note that this mitigation may adversely affect the functionality of email clients.
Currently we are not aware of any vendor-supplied patches. If you feel we are in error or if you are aware of more recent information, please mail us at: firstname.lastname@example.org. NOTE: This ActiveX control is not marked 'safe for scripting' and would therefore prompt the victim before executing the script. Typically, we would not classify this issue as a security vulnerability. However, given the nature of the issue and the existence of exploit code in the wild, this BID will not be retired so that a record of the issue can be maintained.
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