Strategic Overview
- Status
- Patched in 3.2.1
- Affected Plugin
- Companion Auto Update
- Affected Version
< 3.2.1- CVSS
- 9.8Critical
- Weakness type
- CWE-98 · Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
- CVE
CVE-2018-20973
At a glance
CVE-2018-20973 is a critical-severity Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in the Companion Auto Update WordPress plugin, affecting versions < 3.2.1. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 3.2.1; sites on affected versions should update now. Disclosed October 2018.
Vulnerability Overview
The companion-auto-update plugin before 3.2.1 for WordPress has local file inclusion via $_GET['tab'].'.php' parameter in /companion-auto-update.php.
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')
Companion Auto Update < 3.2.1 carries this weakness at tab, 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. For Companion Auto Update the fix is 3.2.1: builds < 3.2.1 are affected, anything from 3.2.1 onward is not.
Remediation
Update to version 3.2.1, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Companion Auto Update: 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. None of that substitutes for the fix: Companion Auto Update 3.2.1 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
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