CVE-2023-23735

Spectra – WordPress Gutenberg Blocks <= 2.3.1 - HTML Injection in Emails

2023-01-23 00:00

Strategic Overview

Status: Patched in 2.3.2
Affected Plugin: Spectra Legacy – Gutenberg Blocks
Affected Version: <= 2.3.1
CVSS: 6.5Medium
Weakness type: CWE-20 · Improper Input Validation
CVE: CVE-2023-23735

View all Spectra Legacy – Gutenberg Blocks vulnerabilities

At a glance

CVE-2023-23735 is a medium-severity Improper Input Validation vulnerability in the Spectra Legacy WordPress plugin, affecting versions <= 2.3.1. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 2.3.2; sites on affected versions should update now. Disclosed January 2023, reported by Dave Jong.

Vulnerability Overview

The Spectra – WordPress Gutenberg Blocks plugin for WordPress is vulnerable to HTML injection via Email in versions up to, and including, 2.3.1. This is due to insufficient input validation and output escaping of content being sent via email. This makes it possible for unauthenticated attackers to send emails to unsuspecting victims with content containing HTML.

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-20: Improper Input Validation

Reaching this weakness in Spectra Legacy <= 2.3.1 takes a caller who can reach the endpoint. Improper input validation means the application accepts input without confirming it has the form, type or range the code downstream assumes.

The concrete impact depends on where the unvalidated value lands, which is why records in this class range from cosmetic bugs to full compromise. For Spectra Legacy the fix is 2.3.2: builds <= 2.3.1 are affected, anything from 2.3.2 onward is not.

Remediation

Update to version 2.3.2, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Spectra Legacy: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Spectra Legacy 2.3.2 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-23735 https://www.wordfence.com/threat-intel/vulnerabilities/id/73323c62-c23f-4bf2-b266-df63db63d4d3 https://nvd.nist.gov/vuln/detail/CVE-2023-23735

Related records

Same weakness class

4.3CVE-2026-10827: Spectra Legacy – Gutenberg Blocks CSS InjectionCVE-2026-10827

Other vulnerabilities in Spectra Legacy – Gutenberg Blocks

CVSS Vector

6.5

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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