[R2] Tenable Nessus Web UI /feed Method Remote Version Disclosure

Nessus contains a flaw in the Web Server that may lead to an unauthorized information disclosure. The issue is triggered when a remote attacker makes a request for the /feed method, which discloses the software's version resulting in a loss of confidentiality. While such information is relatively low risk, it is often useful in carrying out additional, more focused attacks.

* Please note that according to the CVSSv2 guidelines, a partial confidentiality disclosure consists of "considerable informational disclosure. Access to some system files is possible, but the attacker does not have control over what is obtained, or the scope of the loss is constrained. An example is a vulnerability that divulges only certain tables in a database". By this definition, Tenable does not agree that this issue warrants a 'partial confidentiality' rating. As such, we are rating this as 'none' which puts the CVSSv2 score at 0.0. Unfortunately, this is a limitation of CVSS in scoring as there is no way to abstract between a very minor information disclosure (e.g. server banner, path disclosure) versus something more serious. We recognize that this issue may pose a small risk in some environments. Finally, as always, Tenable recommends that Nessus web server interfaces not be exposed to external networks unless absolutely required.