April 9, 2007
The Microsoft Windows Help File viewer is reported prone to a heap-overflow vulnerability because it fails to perform boundary checks before copying user-supplied data into insufficiently sized memory buffers.
This vulnerability presents itself when the application handles a specially crafted Windows Help ('.hlp') file.
A successful attack may facilitate arbitrary code execution in the context of a vulnerable user who opens a malicious file. Failed exploit attempts will likely result in denial-of-service conditions.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to requests that include NOP sleds and unexplained incoming and outgoing traffic. This may indicate exploitation attempts or activity that results from successful exploits.
Do not accept or execute files from untrusted or unknown sources.
Users should refrain from accepting or opening files that originate from an untrusted or unfamiliar source.
Do not follow links provided by unknown or untrusted sources.
User should avoid following links that originate from questionable or untrusted sources.
Implement multiple redundant layers of security.
Since this issue may be leveraged to execute code, we recommend memory-protection schemes, such as non-executable stack/heap configurations and randomly mapped memory segments. This tactic may complicate exploitation of memory-corruption vulnerabilities.
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or if you are aware of more recent information, please mail us at: firstname.lastname@example.org.
Mati Aharoni is credited with discovering this issue.
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