CVE-2022-0418 in Event List Plugin
Summary
by MITRE • 05/02/2022
The Event List WordPress plugin before 0.8.8 does not sanitise and escape some of its settings, allowing high privilege users such as admin to perform Cross-Site Scripting attacks against other admin even when the unfiltered_html is disallowed
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Analysis
by VulDB Data Team • 05/05/2022
The Event List WordPress plugin vulnerability CVE-2022-0418 represents a critical cross-site scripting flaw that undermines the security posture of WordPress installations. This vulnerability affects versions prior to 0.8.8 and specifically targets the plugin's handling of user settings within the WordPress admin environment. The flaw arises from inadequate input sanitization and output escaping mechanisms within the plugin's codebase, creating a pathway for malicious actors to inject malicious scripts into the application's administrative interfaces.
The technical nature of this vulnerability stems from the plugin's failure to properly sanitize user inputs that are subsequently rendered in the admin dashboard. When high privilege users such as administrators interact with the plugin's settings interface, the application fails to escape potentially dangerous characters and script tags that could be embedded within configuration parameters. This oversight allows attackers with administrative privileges to craft malicious payloads that persist within the plugin's settings, which then execute whenever other administrators view the affected pages. The vulnerability is particularly concerning because it specifically targets scenarios where the WordPress environment has unfiltered_html capability disabled, which is a standard security hardening practice that should prevent such attacks.
The operational impact of CVE-2022-0418 extends beyond simple script execution, as it enables attackers to potentially escalate their privileges and compromise entire WordPress installations. When an administrator views pages containing the maliciously injected scripts, these scripts execute in the context of the administrator's browser session, potentially allowing attackers to steal session cookies, modify plugin settings, or even redirect administrators to malicious sites. The vulnerability operates under the CWE-79 principle of cross-site scripting, where the application fails to properly validate and sanitize user-supplied data before rendering it in the browser. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as attackers can leverage the persistent script execution to maintain access and perform further malicious activities within the compromised WordPress environment.
The exploitation of this vulnerability requires an attacker to already possess administrative privileges, which makes it less likely to be exploited by casual attackers but still poses a significant risk to organizations with compromised admin accounts or those using weak credential management practices. The vulnerability's persistence in the settings configuration means that even if an administrator attempts to manually correct the malicious entries, the sanitization issues remain in place, allowing the attack to persist until the plugin is properly updated. Organizations should prioritize updating to version 0.8.8 or later immediately, as this represents the first patched version that addresses the input sanitization and output escaping deficiencies. Additionally, implementing proper input validation at multiple layers of the application stack and ensuring that all user-supplied data undergoes appropriate sanitization before being stored or displayed provides additional defense-in-depth measures against similar vulnerabilities. The vulnerability demonstrates the critical importance of proper security practices in plugin development, particularly when handling user inputs in administrative interfaces where the potential for privilege escalation exists.