Security specialist @Stake Inc. has said that a module that ships with Sun Microsystems Inc.’s One Application Server has a flaw which could be exploited by outside attackers and which could give them control of the running Web server.

The flaw is in the Connector Module, a Netscape Server Application Programming Interface (NSAPI) plug-in that integrates the Sun One Web Server with the Application Server.

An overly long URI (Uniform Resource Indicator) in an incoming HTTP (Hypertext Transfer Protocol) request handled by the module could cause a stack buffer overflow, @Stake said in an advisory Thursday.

The flaw affects Sun One Application Server 6.0 and Sun One Application Server 6.5. A patch is available for version 6.5 at


No patch is available for version 6.0, according to @Stake, but there are a number of workarounds.

These include:

– writing an NSAPI module to inspect the length of HTTP request URIs;

– terminating the SSL (Secure Sockets Layer) session on a device before the Sun ONE Web server and installing an Intrusion Detection System (IDS) sensor to monitor the clear-text traffic;

– terminating the SSL session on a reverse proxy that performs data validation on all HTTP request headers.