CVE-2021-24288

AcyMailing SMTP Newsletter < 7.5.0 - Open Redirect

2021-04-29 00:00

Strategic Overview

Status: Patched in 7.5.0
Affected Plugin: AcyMailing – An Ultimate Newsletter Plugin and Marketing Automation Solution for WordPress
Affected Version: < 7.5.0
CVSS: 6.1Medium
Weakness type: CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE: CVE-2021-24288

View all AcyMailing – An Ultimate Newsletter Plugin and Marketing Automation Solution for WordPress vulnerabilities

At a glance

CVE-2021-24288 is a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the AcyMailing WordPress plugin, affecting versions < 7.5.0. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 7.5.0; sites on affected versions should update now. Disclosed April 2021, reported by Viktor Markopoulos.

Vulnerability Overview

When subscribing using AcyMailing versions before 7.5.0, the 'redirect' parameter isn't properly sanitized. Turning the request from POST to GET, an attacker can craft a link containing a potentially malicious landing page and send it to the victim.

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.

CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

AcyMailing < 7.5.0 carries this weakness at redirect, and reaching it takes a caller who can reach the endpoint. An open redirect is a page that takes a destination from the request and sends the browser there without checking that the destination belongs to the site.

A link that starts on a trusted domain finishes on an attacker's, which is what makes phishing and consent-screen abuse credible to the person clicking it. For AcyMailing the fix is 7.5.0: builds < 7.5.0 are affected, anything from 7.5.0 onward is not.

Remediation

Update to version 7.5.0, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to AcyMailing: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: AcyMailing 7.5.0 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24288 https://www.wordfence.com/threat-intel/vulnerabilities/id/c1acc256-c8f5-4738-8788-d52b4e2b80ef https://nvd.nist.gov/vuln/detail/CVE-2021-24288

Related records

Other vulnerabilities in AcyMailing – An Ultimate Newsletter Plugin and Marketing Automation Solution for WordPress

CVSS Vector

6.1

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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