Ultimate Member – User Profile, User Registration, Login & Membership Plugin <= 2.0.45 - Arbitrary File Deletion/Read

2019-05-13 00:00
Antony Garand

Strategic Overview

Status
Patched in 2.0.46
Affected Plugin
Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin
Affected Version
<= 2.0.45
CVSS
9.4Critical
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the Ultimate Member WordPress plugin, affecting versions <= 2.0.45. It carries a CVSS score of 9.4 (reachable over the network; low attack complexity; high confidentiality, integrity impact). Exploitation requires no authentication. The issue is fixed in version 2.0.46; sites on affected versions should update now. Disclosed May 2019, reported by Antony Garand.

Vulnerability Overview

The Ultimate Member – User Profile, User Registration, Login & Membership Plugin plugin for WordPress is vulnerable to arbitrary file deletion and reading when the file upload functionality is enabled for the user profile and registration forms in versions up to, and including 2.0.45. This is due to the fact that the plugin did not perform sufficient file path validation or restrict the files that users had access to when performing a file download or deletion. This makes it possible for low-level privileged attackers to delete arbitrary files such as the wp-config.php file and ultimately achieve remote code execution.

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.

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Reaching this weakness in Ultimate Member <= 2.0.45 takes a caller who can reach the endpoint. Path traversal happens when user-controlled text is used to build a filesystem path without being constrained to an intended directory, so sequences like ../ walk the resolved path somewhere else.

Depending on the operation, it means reading files outside the intended folder — wp-config.php being the usual target — or writing to and deleting paths the web server can touch. For Ultimate Member the fix is 2.0.46: builds <= 2.0.45 are affected, anything from 2.0.46 onward is not.

Remediation

Update to version 2.0.46, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Ultimate Member: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Ultimate Member 2.0.46 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/618f644b-a92c-4f7f-aaea-c03ee7d6e0f9

Related records

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