CVE-2023-6559

MW WP Form <= 5.0.3 - Improper Limitation of File Name to Unauthenticated Arbitrary File Deletion

2023-12-15 00:00
Thomas Sanzey

Strategic Overview

Status
Patched in 5.0.4
Affected Plugin
MW WP Form
Affected Version
<= 5.0.3
CVSS
7.5High
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE
CVE-2023-6559
View all MW WP Form vulnerabilities

At a glance

CVE-2023-6559 is a high-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the MW WP Form WordPress plugin, affecting versions <= 5.0.3. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high integrity impact). Exploitation requires no authentication. The issue is fixed in version 5.0.4; sites on affected versions should update now. Disclosed December 2023, reported by Thomas Sanzey.

Vulnerability Overview

The MW WP Form plugin for WordPress is vulnerable to arbitrary file deletion in all versions up to, and including, 5.0.3. This is due to the plugin not properly validating the path of an uploaded file prior to deleting it. This makes it possible for unauthenticated attackers to delete arbitrary files, including the wp-config.php file, which can make site takeover and remote code execution possible.

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 integrity.

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

Reaching this weakness in MW WP Form <= 5.0.3 takes no account at all. 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 MW WP Form the fix is 5.0.4: builds <= 5.0.3 are affected, anything from 5.0.4 onward is not.

Remediation

Update to version 5.0.4, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: MW WP Form 5.0.4 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-6559https://www.wordfence.com/threat-intel/vulnerabilities/id/412d555c-9bbd-42f5-8020-ccfc18755a79https://nvd.nist.gov/vuln/detail/CVE-2023-6559

Related records

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