CVE-2020-36157

Ultimate Member <= 2.1.11 - Unauthenticated Privilege Escalation via User Roles

2020-11-09 00:00
Chloe Chamberland

At a glance

CVE-2020-36157 is a critical-severity Improper Privilege Management vulnerability in the Ultimate Member WordPress plugin, affecting versions < 2.1.12. It carries a CVSS score of 10.0 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 2.1.12; sites on affected versions should update now. Disclosed November 2020, reported by Chloe Chamberland.

Vulnerability Overview

An issue was discovered in the Ultimate Member plugin before 2.1.12 for WordPress, aka Unauthenticated Privilege Escalation via User Roles. Due to the lack of filtering on the role parameter that could be supplied during the registration process, an attacker could supply the role parameter with a WordPress capability (or any custom Ultimate Member role) and effectively be granted those privileges.

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-269: Improper Privilege Management

Reaching this weakness in Ultimate Member < 2.1.12 takes no account at all. Improper privilege management means the code lets an account end up with capabilities its role should not have.

It converts a low-privileged account into an administrative one, which makes every other restriction on the site irrelevant. For Ultimate Member the fix is 2.1.12: builds < 2.1.12 are affected, anything from 2.1.12 onward is not.

Remediation

Update to version 2.1.12, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: Ultimate Member 2.1.12 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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