CVE-2020-11030 in WordPress
Summary
by MITRE
In affected versions of WordPress, a special payload can be crafted that can lead to scripts getting executed within the search block of the block editor. This requires an authenticated user with the ability to add content. This has been patched in version 5.4.1, along with all the previously affected versions via a minor release (5.3.3, 5.2.6, 5.1.5, 5.0.9, 4.9.14, 4.8.13, 4.7.17, 4.6.18, 4.5.21, 4.4.22, 4.3.23, 4.2.27, 4.1.30, 4.0.30, 3.9.31, 3.8.33, 3.7.33).
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Analysis
by VulDB Data Team • 06/04/2024
The vulnerability identified as CVE-2020-11030 represents a critical cross-site scripting flaw within the WordPress block editor ecosystem that specifically targets the search block functionality. This security weakness exists in multiple WordPress versions from 3.8 through 5.4, creating a persistent threat vector that allows authenticated attackers to inject malicious scripts into the content management system. The vulnerability is particularly concerning because it leverages the block editor's search capabilities to execute arbitrary code, bypassing standard security controls that typically protect against such attacks. The flaw operates through a carefully crafted payload that exploits insufficient input validation and output escaping mechanisms within the search block implementation.
The technical exploitation of this vulnerability requires an authenticated user with content creation privileges, which significantly reduces the attack surface but does not eliminate the risk entirely. Attackers can leverage this privilege to inject malicious scripts that will execute whenever the search block is rendered within the editor interface. This creates a persistent threat where legitimate users who interact with the content may inadvertently trigger the malicious code execution. The vulnerability stems from inadequate sanitization of user-provided data within the search block's processing pipeline, allowing specially crafted input to bypass security filters and execute within the browser context of other users who view or interact with the affected content.
The operational impact of CVE-2020-11030 extends beyond simple script execution, as it can enable attackers to perform various malicious activities including credential theft, session hijacking, and data exfiltration. The vulnerability affects WordPress installations across multiple major versions, making it a widespread concern for organizations maintaining legacy systems. When exploited, this vulnerability allows attackers to compromise user sessions and potentially escalate privileges within the WordPress environment. The attack chain typically involves an authenticated user creating malicious content within the search block, which then executes when other users access the editor or view pages containing the compromised content.
Security professionals should note that this vulnerability aligns with CWE-79, which describes cross-site scripting flaws in web applications, and maps to attack patterns in the MITRE ATT&CK framework under the initial access and execution categories. The vulnerability demonstrates the importance of input validation and output escaping in web application security, particularly within rich text editors and content management systems. Organizations should prioritize immediate patching of all affected WordPress versions, with the recommended approach being the upgrade to WordPress 5.4.1 or the applicable minor releases that contain the necessary security fixes. The patch addresses the root cause by implementing proper input sanitization and output escaping mechanisms within the search block processing logic, preventing malicious payloads from being executed within the editor environment.