CVE-2020-36838

Facebook Chat Plugin <= 1.5 - Missing Capabilities Check

2020-08-04 00:00

Strategic Overview

Status: Patched in 1.6
Affected Plugin: Facebook Chat Plugin – Live Chat Plugin for WordPress
Affected Version: < 1.6
CVSS: 7.4High
Weakness type: CWE-284 · Improper Access Control
CVE: CVE-2020-36838

View all Facebook Chat Plugin – Live Chat Plugin for WordPress vulnerabilities

At a glance

CVE-2020-36838 is a high-severity Improper Access Control vulnerability in the Facebook Chat Plugin WordPress plugin, affecting versions < 1.6. It carries a CVSS score of 7.4 (reachable over the network; low attack complexity). The issue is fixed in version 1.6; sites on affected versions should update now. Disclosed August 2020, reported by Chloe Chamberland.

Vulnerability Overview

The Facebook Chat Plugin for WordPress is vulnerable to authorization bypass due to a missing capability check on the wp_ajax_update_options function in versions up to, and including, 1.5. This flaw makes it possible for low-level authenticated attackers to connect their own Facebook Messenger account to any site running the vulnerable plugin and engage in chats with site visitors on affected sites.

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-284: Improper Access Control

Reaching this weakness in Facebook Chat Plugin < 1.6 takes a caller who can reach the endpoint. Improper access control means the code decides what a caller may do using something other than their actual permissions, so the decision can be wrong without any check appearing to be missing.

Whoever can shape the request decides the answer, so the protected action runs for callers the code never meant to allow. For Facebook Chat Plugin the fix is 1.6: builds < 1.6 are affected, anything from 1.6 onward is not.

Remediation

Update to version 1.6, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Facebook Chat Plugin 1.6 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2020-36838 https://www.wordfence.com/threat-intel/vulnerabilities/id/36ae4183-5fa7-484c-b858-5df10ae3d3f2 https://nvd.nist.gov/vuln/detail/CVE-2020-36838

Related records

Other vulnerabilities in Facebook Chat Plugin – Live Chat Plugin for WordPress

4.3Facebook Chat Plugin <= 1.2 CSRF to Site Settings Changes

CVSS Vector

7.4

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityLow

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