CVE-2019-20361

Email Subscribers & Newsletters < 4.3.1 - Unauthenticated Blind SQL Injection

2019-11-13 00:00

Strategic Overview

Status: Patched in 4.3.1
Affected Plugin: Email Subscribers & Newsletters – Email Marketing, Post Notifications & Newsletter Plugin for WordPress
Affected Version: <= 4.3.0
CVSS: 8.3High
Weakness type: CWE-89 · Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CVE: CVE-2019-20361

View all Email Subscribers & Newsletters – Email Marketing, Post Notifications & Newsletter Plugin for WordPress vulnerabilities

At a glance

CVE-2019-20361 is a high-severity Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in the Email Subscribers & Newsletters WordPress plugin, affecting versions <= 4.3.0. It carries a CVSS score of 8.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.3.1; sites on affected versions should update now. Disclosed November 2019, reported by Matt Barry.

Vulnerability Overview

There was a flaw in the WordPress plugin, Email Subscribers & Newsletters before 4.3.1, that allowed SQL statements to be passed to the database in the hash parameter (a blind SQL injection vulnerability).

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-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

Reaching this weakness in Email Subscribers & Newsletters <= 4.3.0 takes no account at all. SQL injection happens when request data is concatenated into a query instead of being bound as a parameter, letting an attacker change the structure of the statement rather than just its values.

A working injection can read any table the database user can see, which on a WordPress install means user records, password hashes and session or API secrets stored in options. For Email Subscribers & Newsletters the fix is 4.3.1: builds <= 4.3.0 are affected, anything from 4.3.1 onward is not.

Remediation

Update to version 4.3.1, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Email Subscribers & Newsletters 4.3.1 closes this, and updating the plugin is the step that ends it.

Firewall
Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2019-20361 https://www.wordfence.com/threat-intel/vulnerabilities/id/00187815-6706-4ec9-a566-4836de0d17c6 https://nvd.nist.gov/vuln/detail/CVE-2019-20361

Related records

Same weakness class

Other vulnerabilities in Email Subscribers & Newsletters – Email Marketing, Post Notifications & Newsletter Plugin for WordPress

CVSS Vector

8.3

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

Base

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

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