Blog2Social: Social Media Auto Post & Scheduler < 5.0.1 - PHP Object Injection

2018-09-21 00:00
Plugin Vulnerabilities

Strategic Overview

Status
Patched in 5.0.1
Affected Plugin
Blog2Social: Social Media Auto Post & Scheduler
Affected Version
< 5.0.1
CVSS
7.4High
Weakness type
CWE-502 · Deserialization of Untrusted Data
CVE
CVE pending
View all Blog2Social: Social Media Auto Post & Scheduler vulnerabilities

At a glance

This record tracks a high-severity Deserialization of Untrusted Data vulnerability in the Blog2Social WordPress plugin, affecting versions < 5.0.1. It carries a CVSS score of 7.4 (reachable over the network; low attack complexity). The issue is fixed in version 5.0.1; sites on affected versions should update now. Disclosed September 2018, reported by Plugin Vulnerabilities.

Vulnerability Overview

The Blog2Social: Social Media Auto Post & Scheduler plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 5.0.0 via deserialization of untrusted input in the vulnerable function named curationShare. This allows authenticated attackers to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

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.

CWE-502: Deserialization of Untrusted Data

Reaching this weakness in Blog2Social < 5.0.1 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 Blog2Social the fix is 5.0.1: builds < 5.0.1 are affected, anything from 5.0.1 onward is not.

Remediation

Update to version 5.0.1, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Blog2Social: 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: Blog2Social 5.0.1 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/6b8655a6-f410-480d-8c45-2527b53fa129

Related records

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