ISAPI filter

ISAPI filter

(World-Wide Web)
A replaceable DLL which the server calls whenever there is an HTTP request. When the filter is first loaded, it communicates to the server what sort of notifications will be accepted. After that, whenever a selected event occurs, the filter is called to process the event.

Example applications of ISAPI filters include custom authentication schemes, compression, encryption, logging, traffic analysis or other request analyses.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)
References in periodicals archive ?
The second is a malicious ISAPI filter. An ISAPI filter is a file that can enhance the functionality of Microsoft's Internet Information Services.
(To be a geek for a moment, it is a buffer overrun in the IDA/IDQ ISAPI filter.) That the vulnerability had such a designation implies that Microsoft was aware of it and had issued a bulletin on the vulnerability in question.
* Web server integration -- supporting the most widely deployed web server technologies including Microsoft IIS via ISAPI filters, and Apache with extensions.