CVE-2022-36371

My Calendar <= 3.3.16 - Open Redirect

2022-08-02 00:00

Strategic Overview

Status: Patched in 3.3.17
Affected Plugin: My Calendar – Accessible Event Manager
Affected Version: <= 3.3.16
CVSS: 4.7Medium
Weakness type: CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE: CVE-2022-36371

View all My Calendar – Accessible Event Manager vulnerabilities

At a glance

CVE-2022-36371 is a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the My Calendar WordPress plugin, affecting versions <= 3.3.16. It carries a CVSS score of 4.7 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 3.3.17; sites on affected versions should update now. Disclosed August 2022, reported by Dan Kegel.

Vulnerability Overview

The My Calendar plugin for WordPress is vulnerable to Open Redirection in versions up to, and including, 3.3.16. This makes it possible for unauthenticated attackers to create links that look to be part of an affected site, but will redirect to the attacker's target. This vulnerability can be utilized for malicious redirection and can also be used for phishing.

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')

Reaching this weakness in My Calendar <= 3.3.16 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 My Calendar the fix is 3.3.17: builds <= 3.3.16 are affected, anything from 3.3.17 onward is not.

Remediation

Update to version 3.3.17, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to My Calendar: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: My Calendar 3.3.17 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2022-36371 https://www.wordfence.com/threat-intel/vulnerabilities/id/6e77d240-475d-41a2-9b88-1332fc60b72d https://nvd.nist.gov/vuln/detail/CVE-2022-36371

Related records

Other vulnerabilities in My Calendar – Accessible Event Manager

CVSS Vector

4.7

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

Base

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

This record contains material that is subject to copyright

CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

https://www.cve.org/Legal/TermsOfUse

Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy.

https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/