CVE-2021-37598

WP Cerber < 8.9.3 - Access Bypass Control

2021-08-16 00:00
Aaron Carreras

Strategic Overview

Status
Patched in 8.9.3
Affected Version
< 8.9.3
CVSS
5.3Medium
Weakness type
CWE-284 · Improper Access Control
CVE
CVE-2021-37598
View all WP Cerber Security, Anti-spam & Malware Scan vulnerabilities

At a glance

CVE-2021-37598 is a medium-severity Improper Access Control vulnerability in the WP Cerber Security, Anti-spam & Malware Scan WordPress plugin, affecting versions < 8.9.3. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 8.9.3; sites on affected versions should update now. Disclosed August 2021, reported by Aaron Carreras.

Vulnerability Overview

WP Cerber before 8.9.3 allows bypass of /wp-json access control via a trailing ? character.

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.

CWE-284: Improper Access Control

Reaching this weakness in WP Cerber Security, Anti-spam & Malware Scan < 8.9.3 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 WP Cerber Security, Anti-spam & Malware Scan the fix is 8.9.3: builds < 8.9.3 are affected, anything from 8.9.3 onward is not.

Remediation

Update to version 8.9.3, 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: WP Cerber Security, Anti-spam & Malware Scan 8.9.3 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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