Strategic Overview
- Status
- Patched in 1.1.6
- Affected Plugin
- bbPress Move Topics
- Affected Version
<= 1.1.4- CVSS
- 8.8High
- Weakness type
- CWE-502 · Deserialization of Untrusted Data
- CVE
CVE-2018-21005
At a glance
CVE-2018-21005 is a high-severity Deserialization of Untrusted Data vulnerability in the bbPress Move Topics WordPress plugin, affecting versions <= 1.1.4. 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 1.1.6; sites on affected versions should update now. Disclosed March 2018.
Vulnerability Overview
The bbPress Move Topics plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 1.1.4 via deserialization of untrusted input via the 'aforums_move_topics_page()' function where it passes the decoded 'allforums' value through the 'unserialize()' function. This allows authenticated attackers to inject a PHP Object.
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
bbPress Move Topics <= 1.1.4 carries this weakness at allforums, 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 bbPress Move Topics the fix is 1.1.6: builds <= 1.1.4 are affected, anything from 1.1.6 onward is not.
Remediation
Update to version 1.1.6, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to bbPress Move Topics: 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: bbPress Move Topics 1.1.6 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Other vulnerabilities in bbPress Move Topics
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