Bit File Manager <= 4.1.4 - Cross-Site Request Forgery to Arbitrary File Upload

2017-03-01 00:00
David Vaartjes

Strategic Overview

Status
Patched in 4.1.5
Affected Plugin
File Manager
Affected Version
< 4.1.5
CVSS
8.8High
Weakness type
CWE-352 · Cross-Site Request Forgery (CSRF)
CVE
CVE pending
View all File Manager vulnerabilities

At a glance

This record tracks a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the File Manager WordPress plugin, affecting versions < 4.1.5. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 4.1.5; sites on affected versions should update now. Disclosed March 2017, reported by David Vaartjes.

Vulnerability Overview

The Bit File Manager plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 4.1.4. This is due to missing or incorrect nonce validation on the plugin's upload form. This makes it possible for unauthenticated attackers to upload arbitrary files to the server via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-352: Cross-Site Request Forgery (CSRF)

Reaching this weakness in File Manager < 4.1.5 takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For File Manager the fix is 4.1.5: builds < 4.1.5 are affected, anything from 4.1.5 onward is not.

Remediation

Update to version 4.1.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to File Manager: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: File Manager 4.1.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/37052cb9-8479-4004-9161-65f37028ae10

Related records

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