CVE-2023-34110 in Flask-AppBuilder
Summary
by MITRE • 06/23/2023
Flask-AppBuilder is an application development framework, built on top of Flask. Prior to version 4.3.2, an authenticated malicious actor with Admin privileges, could by adding a special character on the add, edit User forms trigger a database error, this error is surfaced back to this actor on the UI. On certain database engines this error can include the entire user row including the pbkdf2:sha256 hashed password. This vulnerability has been fixed in version 4.3.2.
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Analysis
by VulDB Data Team • 06/23/2023
This vulnerability exists within the Flask-AppBuilder framework, a popular application development toolkit built upon the Flask web framework. The flaw represents a critical information disclosure issue that specifically affects administrators with elevated privileges. The vulnerability stems from inadequate input validation and error handling mechanisms within the user management functionality of the framework. Attackers with admin-level access can exploit this weakness by injecting specially crafted characters into the user addition or editing forms, which then triggers database-level errors that are subsequently displayed to the attacker through the user interface.
The technical exploitation occurs when an authenticated malicious actor with administrative privileges manipulates the input fields during user creation or modification operations. The framework fails to properly sanitize user-supplied data before processing it through database operations, leading to database errors that contain sensitive information. This particular vulnerability manifests differently across various database engines, but on certain systems the error messages include complete database rows containing password hashes. The pbkdf2:sha256 hashed passwords are exposed through these error messages, representing a significant compromise of system security since these hashes could potentially be targeted through offline cracking attacks or used in further exploitation attempts.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with access to password hash data that could facilitate credential compromise. The vulnerability affects all versions prior to 4.3.2, meaning organizations using older versions of Flask-AppBuilder are at risk of exposing sensitive authentication data. This represents a direct violation of security principles where error handling should never expose sensitive system information to unauthorized users. The flaw aligns with CWE-209, which addresses "Information Exposure Through an Error Message," and specifically demonstrates how improper error handling can lead to credential exposure. From an attack perspective, this vulnerability maps to techniques described in the ATT&CK framework under credential access and information discovery tactics.
Organizations should immediately upgrade to version 4.3.2 or later to remediate this vulnerability, as the fix addresses the root cause through improved input validation and error handling mechanisms. The mitigation strategy should include comprehensive testing of user management functions to ensure that error messages no longer expose database-level information. Additionally, administrators should implement proper access controls and monitoring to detect unusual activity patterns that might indicate exploitation attempts. The vulnerability highlights the importance of robust error handling practices and the principle of least privilege, where even administrative users should not be able to access sensitive system information through error messages. Security teams should also consider implementing database-level protections and monitoring for unusual query patterns that might indicate exploitation attempts.