CVE-2023-33972 in Scylladb
Summary
by MITRE • 10/25/2023
Scylladb is a NoSQL data store using the seastar framework, compatible with Apache Cassandra. Authenticated users who are authorized to create tables in a keyspace can escalate their privileges to access a table in the same keyspace, even if they don't have permissions for that table. This issue has not yet been patched. A workaround to address this issue is to disable CREATE privileges on a keyspace, and create new tables on behalf of other users.
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Analysis
by VulDB Data Team • 10/25/2023
The vulnerability identified as CVE-2023-33972 affects ScyllaDB, a high-performance NoSQL database system built on the seastar framework and designed to be compatible with Apache Cassandra. This security flaw represents a significant privilege escalation issue that undermines the database's access control mechanisms. The vulnerability specifically targets authenticated users who possess the ability to create tables within a keyspace, allowing them to subsequently access tables they should not have permission to view or modify. This represents a direct violation of the principle of least privilege that forms the foundation of secure database access controls. The flaw exists at the authorization layer of the database system, where the permission checking mechanism fails to properly validate access rights when users attempt to interact with tables they have not been explicitly granted permissions for. The vulnerability affects the core data protection mechanisms of ScyllaDB, potentially allowing unauthorized data access and manipulation that could compromise sensitive information stored within the database.
The technical implementation of this vulnerability stems from improper access control validation within the ScyllaDB authorization framework. When authenticated users with CREATE privileges execute table creation operations within a keyspace, the system incorrectly grants them elevated access rights that extend beyond their original authorization scope. This flaw manifests in the way the database system handles table-level permissions during and after table creation operations, where the permission validation logic fails to properly enforce access restrictions. The vulnerability is particularly concerning because it operates at the keyspace level, meaning that users who can create tables in a keyspace can potentially access all tables within that same keyspace regardless of their individual table permissions. This creates a scenario where a user with limited table access can leverage their ability to create tables as a means to gain broader access to the entire keyspace's data. The flaw demonstrates a classic authorization bypass vulnerability that allows for privilege escalation through legitimate database operations, making it particularly difficult to detect and mitigate.
The operational impact of CVE-2023-33972 extends beyond simple data access violations to encompass potential data integrity and confidentiality breaches within ScyllaDB environments. Organizations relying on ScyllaDB for critical data storage may experience unauthorized data exposure, where users can access sensitive information that should be restricted to specific authorized personnel. This vulnerability undermines the trust model that database systems rely on for maintaining data security, as it allows for unauthorized access to data that has been explicitly restricted through permission controls. The impact is particularly severe in multi-tenant environments or organizations with strict data governance requirements, where different user groups need to be isolated from each other's data. The vulnerability also creates potential for data manipulation or deletion attacks, as users who can access tables through this privilege escalation method may also be able to modify or destroy data within those tables. This type of authorization bypass vulnerability aligns with CWE-285, which addresses improper authorization issues in software systems. The flaw essentially creates a backdoor through which users can bypass normal access controls, representing a serious weakness in the database's security architecture.
The recommended mitigation strategy for CVE-2023-33972 focuses on implementing immediate workarounds while awaiting official patches from ScyllaDB. The primary workaround involves disabling CREATE privileges on keyspaces and instead creating tables on behalf of other users, effectively preventing the privilege escalation path that leads to the vulnerability. This approach requires administrators to carefully manage table creation operations and ensure that only trusted users with appropriate authorization levels can perform these operations. Organizations should also implement comprehensive monitoring of table creation activities and access patterns to detect potential exploitation attempts. The workaround essentially shifts the table creation responsibility to administrators or privileged users, thereby eliminating the ability of regular users to leverage their CREATE privileges for unauthorized access. This mitigation approach aligns with the principle of least privilege and represents a defensive measure that can be implemented immediately while longer-term solutions are developed. Security teams should also consider implementing additional access controls, such as role-based access control enhancements or more granular permission settings, to further protect against potential exploitation. The vulnerability's existence highlights the importance of regular security assessments and patch management processes, as well as the need for comprehensive testing of authorization mechanisms within database systems. Organizations should review their current access control configurations and validate that proper segregation of duties exists between table creation and table access operations to prevent similar issues from occurring in other database systems.