CVE-2022-0364 in Modern Events Calendar Lite Plugin
Summary
by MITRE • 03/21/2022
The Modern Events Calendar Lite WordPress plugin before 6.4.0 does not sanitize and escape some of the Hourly Schedule parameters which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks
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Analysis
by VulDB Data Team • 03/23/2022
The vulnerability identified as CVE-2022-0364 affects the Modern Events Calendar Lite WordPress plugin version 6.4.0 and earlier, representing a critical security flaw that enables stored cross-site scripting attacks through insufficient input sanitization. This issue specifically targets the Hourly Schedule parameters within the plugin's functionality, creating a pathway for malicious actors to inject persistent malicious scripts into the application's data storage. The vulnerability's severity is amplified by the fact that it requires minimal user privileges, allowing even users with contributor-level roles to exploit the flaw, which directly violates the principle of least privilege in security design.
The technical implementation of this vulnerability stems from the plugin's failure to properly sanitize and escape user-supplied data within the Hourly Schedule parameters during the data processing phase. When users with contributor roles submit schedule information through the plugin's interface, the application fails to adequately validate or escape the input before storing it in the database. This allows malicious script code to be permanently stored within the application's data structures and subsequently executed whenever the affected data is rendered in the user interface. The flaw operates as a classic stored XSS vulnerability, where the malicious payload persists server-side and executes in the context of other users who view the compromised content, making it particularly dangerous for collaborative environments where multiple users interact with shared data.
The operational impact of this vulnerability extends beyond simple script execution, as it creates a persistent threat vector that can be leveraged for various malicious activities including session hijacking, credential theft, and data exfiltration. Attackers can craft malicious payloads that exploit the stored XSS to steal cookies, redirect users to phishing sites, or even modify the application's behavior through JavaScript manipulation. The vulnerability's exploitation is particularly concerning in WordPress environments where contributor accounts are commonly granted to users who need to create and manage content but should not have elevated privileges. This creates a significant risk for organizations that rely on WordPress for event management, as the compromise of a single contributor account can lead to broader system infiltration and data compromise.
Security professionals should note that this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in software applications. The issue also maps to ATT&CK technique T1566.002, which covers phishing with malicious attachments, as attackers can leverage the stored XSS to deliver malicious payloads through compromised event scheduling data. Organizations should implement immediate mitigations including updating to version 6.4.0 or later of the Modern Events Calendar Lite plugin, implementing proper input validation and output escaping mechanisms, and conducting thorough security audits of all installed WordPress plugins. Additionally, network monitoring should be enhanced to detect suspicious script injection patterns, and user access controls should be reviewed to minimize the number of users with contributor-level privileges who can interact with event scheduling functionality.