CVE-2020-28033

WordPress Core < 5.5.2 - Spam Embed on Multisite Installations

2020-10-29 00:00

Strategic Overview

Status: Patched in 3.7.35
Affected Core: WordPress 5.5
Affected Version: 3.7 – 5.5.1 · 20 branches
CVSS: 4.3Medium
Weakness type: CWE-345 · Insufficient Verification of Data Authenticity
CVE: CVE-2020-28033

At a glance

CVE-2020-28033 is a medium-severity Insufficient Verification of Data Authenticity vulnerability in the WordPress 5.5 WordPress release line, affecting 3.7 – 5.5.1 · 20 branches. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). The issue is fixed in version 3.7.35; sites on affected versions should update now. Disclosed October 2020, reported by David Binovec.

Vulnerability Overview

WordPress before 5.5.2 mishandles embeds from disabled sites on a multisite network, as demonstrated by allowing a spam embed.

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-345: Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

Remediation

Update to one of the following versions, or a newer patched version: 3.7.35, 3.8.35, 3.9.33, 4.0.32, 4.1.32, 4.2.29, 4.3.25, 4.4.24, 4.5.23, 4.6.20, 4.7.19, 4.8.15, 4.9.16, 5.0.11, 5.1.7, 5.2.8, 5.3.5, 5.4.3, 5.5.2

How does WordSec protect against this?

The fix is the thing that ends this: updating to 3.7.35 is the step that ends it.

Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2020-28033 https://www.wordfence.com/threat-intel/vulnerabilities/id/f3ff473c-c629-487c-9b18-e074534c7b79 https://nvd.nist.gov/vuln/detail/CVE-2020-28033

Related records

Same weakness class

8.1CVE-2021-44223: WordPress Core < 5.8 Dependency ConfusionCVE-2021-44223

Other vulnerabilities in WordPress 5.5

CVSS Vector

4.3

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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