CVE-2016-20082

A/B Test for WordPress <= 1.0.7 - Local File Inclusion

2016-03-21 00:00
CrashBandicot

Strategic Overview

Status
Unpatched
Affected Plugin
A/B Test for WordPress
Affected Version
<= 1.0.7
CVSS
9.8Critical
Weakness type
CWE-98 · Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
CVE
CVE-2016-20082
View all A/B Test for WordPress vulnerabilities

At a glance

CVE-2016-20082 is a critical-severity Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in the A/B Test for WordPress WordPress plugin, affecting versions <= 1.0.7. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed March 2016, reported by CrashBandicot.

Vulnerability Overview

The A/B Test for WordPress plugin for WordPress is vulnerable to Local File Inclusion via the 'action' parameter in the 'abtest_admin.php' file in versions up to, and including, 1.0.7. This allows authenticated Admin+ attackers to include and execute arbitrary files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where images and other “safe” file types can be uploaded and included.

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-98: Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')

A/B Test for WordPress <= 1.0.7 carries this weakness at action, and reaching it takes a caller who can reach the endpoint. PHP file inclusion means a path used by include or require is built from request data, so the file that gets executed is under the caller's influence.

Including an attacker-influenced file executes its contents, which is why this class is routinely chained with an upload or log-poisoning step to reach code execution. No fixed build of this plugin is recorded for A/B Test for WordPress yet, so installs running <= 1.0.7 stay exposed until the vendor ships one.

Remediation

No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.

How does WordSec protect against this?

The attempt arrives as an ordinary request to A/B Test for WordPress: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.

  • Firewall
  • Scanner
  • Alerts

External References

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C