CVE-2018-6195

Splashing Images <= 2.1 - PHP Object Injection

2018-01-26 00:00
Nicolas Buzy-Debat

Strategic Overview

Status
Patched in 2.1.1
Affected Plugin
Splashing Images
Affected Version
<= 2.1
CVSS
8.8High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE-2018-6195
View all Splashing Images vulnerabilities

At a glance

CVE-2018-6195 is a high-severity Deserialization of Untrusted Data vulnerability in the Splashing Images WordPress plugin, affecting versions <= 2.1. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). The issue is fixed in version 2.1.1; sites on affected versions should update now. Disclosed January 2018, reported by Nicolas Buzy-Debat.

Vulnerability Overview

admin/partials/wp-splashing-admin-main.php in the Splashing Images plugin (wp-splashing-images) before 2.1.1 for WordPress allows authenticated (administrator, editor, or author) remote attackers to conduct PHP Object Injection attacks via crafted serialized data in the 'session' HTTP GET parameter to wp-admin/upload.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 interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-502: Deserialization of Untrusted Data

Splashing Images <= 2.1 carries this weakness at session, and reaching it takes a caller who can reach the endpoint. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.

A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For Splashing Images the fix is 2.1.1: builds <= 2.1 are affected, anything from 2.1.1 onward is not.

Remediation

Update to version 2.1.1, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Splashing Images: 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: Splashing Images 2.1.1 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

Related records

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