Rule Category

POLICY-OTHER --

Alert Message

POLICY-OTHER Microsoft SharePoint external ImportWeb attempt

Rule Explanation

Rule triggers if - Traffic is destined for SharPoint's URI "/_vti_bin/sites.asmx" - ImportWeb request is being made - request is trying to import file ending with .cmp

What To Look For

This rule detects MS SharePoint's ImportWeb requests originating from external network and trying to import .cmp file. These requests can be used to trigger CVE-2020-17121.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

MITRE ATT&CK Framework

Tactic: Initial Access

Technique: Drive-by Compromise

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org

Additional Links

Rule Vulnerability

Directory Traversal

A Directory Traversal attack targets HTTP traffic and allows the attacker to access directories outside the applications own, potentially exposing sensitive system files to leakage or overwriting. This is also known as Directory Climbing, Path Traversal, or Backtracking. An alert on this kind of attack indicates a vulnerability in security validation of user input that allows a "traverse to parent directory" or "../" command to pass through. Protect your site by filtering all user input, removing any characters but the allowed data.

CVE Additional Information