CVE-2023-0772 in Popup Builder Plugin
Summary
by MITRE • 03/13/2023
The Popup Builder by OptinMonster WordPress plugin before 2.12.2 does not ensure that the campaign to be loaded via some shortcodes is actually a campaign, allowing any authenticated users such as subscriber to retrieve the content of arbitrary posts, like draft, private or even password protected ones.
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Analysis
by VulDB Data Team • 04/04/2023
The vulnerability identified as CVE-2023-0772 affects the Popup Builder plugin for WordPress, specifically versions prior to 2.12.2. This issue represents a critical access control flaw that undermines the security model of the plugin and potentially exposes sensitive content to unauthorized users. The vulnerability stems from insufficient validation of campaign identifiers used in shortcodes, creating a path for authenticated users to bypass normal content access restrictions. The flaw allows any user account with subscriber-level privileges to retrieve content from posts that should normally be restricted, including drafts, private posts, and those protected by passwords. This represents a significant escalation of privileges within the WordPress ecosystem, as users who should only have limited access can gain visibility into content they should not be able to view.
The technical implementation of this vulnerability resides in the plugin's handling of shortcode parameters that reference campaigns. When users invoke specific shortcodes, the plugin should verify that the referenced campaign actually exists and is accessible to the requesting user. However, the vulnerable code fails to perform proper campaign validation checks, allowing arbitrary post IDs to be passed through the shortcode mechanism. This lack of input sanitization and validation creates a direct path for privilege escalation attacks. The vulnerability aligns with CWE-284 Access Control flaws, specifically representing improper access control mechanisms that permit unauthorized access to protected resources. The flaw demonstrates poor security practices in parameter validation and access control enforcement, which are fundamental requirements for maintaining the integrity of content management systems.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can lead to comprehensive data exposure and potential business disruption. Subscribers can access draft content that may contain sensitive business information, strategic plans, or confidential communications that should remain private until publication. Private posts containing proprietary data, customer information, or internal communications become accessible to all authenticated users, creating significant privacy and security risks. Password-protected content, which is typically used to restrict access to specific audiences or content that is not yet ready for public consumption, becomes trivially accessible through this vulnerability. This exposure can result in competitive disadvantage, regulatory compliance violations, and potential legal consequences for organizations that fail to protect sensitive information. The vulnerability also impacts the overall security posture of WordPress installations, as it allows attackers to gather intelligence about content that should remain hidden.
Mitigation strategies for CVE-2023-0772 focus primarily on immediate plugin updates to version 2.12.2 or later, which contain the necessary access control fixes. Administrators should also implement additional monitoring of user activities and shortcode usage patterns to detect potential exploitation attempts. The WordPress security team recommends verifying that all users with subscriber roles have appropriate access restrictions in place and that content access policies are properly enforced throughout the site. Organizations should conduct regular security audits of their WordPress plugins and themes to identify similar access control vulnerabilities. From an ATT&CK perspective, this vulnerability maps to techniques involving privilege escalation and credential access, as it allows users to gain access to content beyond their intended permissions. Network segmentation and additional authentication layers can provide defense in depth, though the primary solution remains the timely application of the vendor-provided security patch. Regular security updates and vulnerability management processes are essential to prevent similar issues from arising in other plugins or components of the WordPress ecosystem.