Ultimate Member <= 1.3.83 - Shortcode Injection

2017-04-17 00:00
James Golovich

Strategic Overview

Status
Patched in 1.3.84
Affected Plugin
Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin
Affected Version
<= 1.3.83
CVSS
9.8Critical
Weakness type
CWE-862 · Missing Authorization
CVE
CVE pending
View all Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin vulnerabilities

At a glance

This record tracks a critical-severity Missing Authorization vulnerability in the Ultimate Member WordPress plugin, affecting versions <= 1.3.83. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 1.3.84; sites on affected versions should update now. Disclosed April 2017, reported by James Golovich.

Vulnerability Overview

The Ultimate Member plugin for WordPress is vulnerable to Executing Arbitrary WordPress Shortcodes in versions up to, and including, 1.3.83. This is due to 'ultimatemember_frontend_modal' AJAX action allowing for the execution of the 'do_shortcode()' function. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.

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, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-862: Missing Authorization

Ultimate Member <= 1.3.83 carries this weakness at ultimatemember_frontend_modal, and reaching it takes a caller who can reach the endpoint. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For Ultimate Member the fix is 1.3.84: builds <= 1.3.83 are affected, anything from 1.3.84 onward is not.

Remediation

Update to version 1.3.84, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Ultimate Member 1.3.84 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/bab67a5c-3390-4423-8fa9-b5ffbc98324d

Related records

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