CVE-2023-28409

MW WP Form <= 4.4.2 - Directory Traversal via _file_upload

2023-05-08 00:00

Strategic Overview

Status: Patched in 4.4.3
Affected Plugin: MW WP Form
Affected Version: < 4.4.3
CVSS: 5.3Medium
Weakness type: CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE: CVE-2023-28409

At a glance

CVE-2023-28409 is a medium-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the MW WP Form WordPress plugin, affecting versions < 4.4.3. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.4.3; sites on affected versions should update now. Disclosed May 2023, reported by Shuya Ota.

Vulnerability Overview

The MW WP Form plugin for WordPress is vulnerable to Directory Traversal in versions up to, and including, 4.4.2 via the _file_upload function. This allows unauthenticated attackers to upload files of allowed types to arbitrary directories on the site.

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.

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

Reaching this weakness in MW WP Form < 4.4.3 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 MW WP Form the fix is 4.4.3: builds < 4.4.3 are affected, anything from 4.4.3 onward is not.

Remediation

Update to version 4.4.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to MW WP Form: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: MW WP Form 4.4.3 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-28409 https://www.wordfence.com/threat-intel/vulnerabilities/id/f7adeee0-30ff-4759-b42e-1ac2dea5a8a4 https://nvd.nist.gov/vuln/detail/CVE-2023-28409

Related records

Same weakness class

Other vulnerabilities in MW WP Form

CVSS Vector

5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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