CVE-2022-3796 in Events Calendar Plugin
Summary
by MITRE • 11/01/2022
A vulnerability was found in Events Calendar Plugin. It has been declared as problematic. This vulnerability affects unknown code of the file post.php of the component Event Handler. The manipulation of the argument title/body leads to cross site scripting. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. The identifier of this vulnerability is VDB-212632.
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Analysis
by VulDB Data Team • 06/11/2026
The vulnerability identified in the Events Calendar Plugin represents a critical cross-site scripting flaw that has been publicly disclosed and is actively being exploited. This weakness resides within the post.php file of the Event Handler component, making it a core element of the plugin's functionality that directly processes user input. The vulnerability specifically manifests when manipulating the title and body arguments of events, creating a pathway for malicious actors to inject harmful scripts into the application's response. The remote exploitation capability means that attackers can leverage this vulnerability without requiring physical access to the system, making it particularly dangerous in web-based environments where the plugin is exposed to external users. The disclosure of this exploit to the public community has significantly increased the risk surface, as threat actors can now readily implement the attack vector without requiring advanced technical knowledge. This vulnerability directly maps to CWE-79, which defines cross-site scripting as a weakness where untrusted data is sent to a web browser without proper validation or sanitization. The attack vector can be classified under the ATT&CK framework as a web application attack, specifically targeting input validation weaknesses in web applications.
The technical implementation of this vulnerability involves the improper handling of user-supplied data within the event creation and management functionality. When users submit event details through the web interface, the title and body fields are processed by the post.php script without adequate sanitization measures. This allows malicious actors to inject script code that will execute in the browsers of other users who view the affected events. The vulnerability's impact extends beyond simple script execution, as it can potentially enable session hijacking, data theft, or redirection to malicious websites. The attack chain typically begins with an attacker creating an event with malicious payloads in the title or body fields, which are then stored in the database and rendered in subsequent page views. The remote nature of the attack means that the vulnerability can be exploited from any location with internet access, making it particularly challenging to monitor and protect against. Security researchers have noted that this type of vulnerability often serves as a stepping stone for more sophisticated attacks, as it can be used to establish a foothold within the target environment.
The operational impact of this vulnerability creates significant risks for organizations that rely on the Events Calendar Plugin for their event management systems. When exploited, the vulnerability can compromise user sessions, steal sensitive information, and potentially allow attackers to gain unauthorized access to administrative functions. The vulnerability affects not only the end users who interact with the calendar but also the administrators who manage the events, as the attack can be executed through normal user interaction with the plugin. Organizations may experience data breaches, loss of user trust, and potential regulatory compliance violations if the vulnerability is exploited successfully. The public disclosure of the exploit has accelerated the timeline for organizations to address the issue, as the window for protection has been significantly reduced. The vulnerability's impact is particularly severe in environments where the plugin is used for business-critical event management, such as in enterprise settings where sensitive scheduling information is managed through the system. The attack can be automated, allowing for rapid exploitation across multiple instances of the plugin, increasing the potential damage scale.
Mitigation strategies for this vulnerability require immediate action from system administrators and security teams. The most effective immediate solution is to apply the vendor-provided security patch or upgrade to a version that addresses the cross-site scripting weakness in the post.php file. Organizations should also implement input validation measures at multiple levels, including client-side and server-side sanitization of event title and body fields. Web application firewalls can be configured to detect and block known malicious patterns in event data submissions. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other components of the web application. Additional protective measures include implementing content security policies that restrict script execution, using secure coding practices for input handling, and establishing monitoring procedures for unusual activity in event management functions. The vulnerability's classification under CWE-79 and its potential mapping to ATT&CK techniques such as web application attacks and credential access emphasize the need for comprehensive security measures. Organizations should also consider implementing network segmentation to limit the potential impact of successful exploitation and establish incident response procedures specifically for web application vulnerabilities. Regular security awareness training for users can help prevent social engineering attacks that might exploit this vulnerability by encouraging users to avoid interacting with suspicious event entries.