CVE-2023-34235 in Strapi
Summary
by MITRE • 07/25/2023
Strapi is an open-source headless content management system. Prior to version 4.10.8, it is possible to leak private fields if one is using the `t(number)` prefix. Knex query allows users to change the default prefix. For example, if someone changes the prefix to be the same as it was before or to another table they want to query, the query changes from `password` to `t1.password`. `password` is protected by filtering protections but `t1.password` is not protected. This can lead to filtering attacks on everything related to the object again, including admin passwords and reset-tokens. Version 4.10.8 fixes this issue.
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Analysis
by VulDB Data Team • 08/18/2023
The vulnerability identified as CVE-2023-34235 affects Strapi, an open-source headless content management system that has gained significant adoption in enterprise and developer environments. This security flaw represents a critical data exposure issue that stems from improper field filtering mechanisms within the database query layer. The vulnerability specifically impacts versions prior to 4.10.8, where the system's protection mechanisms fail to adequately secure private fields when users employ the `t(number)` prefix functionality. The issue manifests through the Knex query builder's ability to modify default table prefixes, creating a pathway for unauthorized data access that bypasses standard security controls.
The technical exploitation of this vulnerability occurs through manipulation of the database query structure where a user can alter the default prefix used by Knex to reference database tables. When a user modifies the prefix to match previous table naming conventions or to reference other tables within the database schema, the system's filtering protections become ineffective. Specifically, while fields named simply as `password` are protected by the system's built-in filtering mechanisms, when the same field is referenced as `t1.password` due to prefix changes, these protections no longer apply. This creates a scenario where attackers can craft queries that access protected information through alternative table references, effectively circumventing the intended security controls.
The operational impact of this vulnerability extends beyond simple data leakage to encompass critical system compromise scenarios. The vulnerability enables attackers to conduct filtering attacks against objects that contain sensitive information including but not limited to admin passwords and password reset tokens. This represents a severe escalation of privileges and data exposure risk that can lead to full system compromise. The vulnerability's potential for widespread impact is amplified by the fact that Strapi is commonly used in production environments where it handles sensitive content and user data. According to CWE classification, this vulnerability aligns with CWE-20: Improper Input Validation, and more specifically CWE-542: Information Exposure Through External Control, as it allows external entities to manipulate system controls to gain unauthorized access to protected information.
The attack vector for this vulnerability leverages the flexibility of the Knex query builder's prefix modification capabilities, which are designed for legitimate database schema management but become exploitable when used maliciously. The vulnerability demonstrates a classic case of insufficient input sanitization where the system fails to validate that table prefixes used in queries maintain proper security boundaries. From an ATT&CK framework perspective, this vulnerability maps to T1213.002: Data from Information Repositories and T1566.001: Phishing, as attackers can exploit this weakness to gain access to sensitive user credentials and system information. The remediation implemented in Strapi version 4.10.8 involves strengthening the filtering mechanisms to ensure that all field references, regardless of their table prefix, maintain consistent protection levels. This fix addresses the core issue by ensuring that the system's security controls are applied uniformly across all database query paths, preventing the bypass of protection mechanisms through prefix manipulation. The vulnerability highlights the importance of maintaining consistent security controls throughout database query layers and demonstrates the critical need for proper input validation and sanitization in systems that handle sensitive data.