CVE-2023-28635 in vantage6
Summary
by MITRE • 10/25/2023
vantage6 is privacy preserving federated learning infrastructure. Prior to version 4.0.0, malicious users may try to get access to resources they are not allowed to see, by creating resources with integers as names. One example where this is a risk, is when users define which users are allowed to run algorithms on their node. This may be defined by username or user id. Now, for example, if user id 13 is allowed to run tasks, and an attacker creates a username with username '13', they would be wrongly allowed to run an algorithm. There may also be other places in the code where such a mixup of resource ID or name leads to issues. Version 4.0.0 contains a patch for this issue. The best solution is to check when resources are created or modified, that the resource name always starts with a character.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/31/2023
The vulnerability described in CVE-2023-28635 affects vantage6, a privacy-preserving federated learning infrastructure platform that enables collaborative machine learning while maintaining data confidentiality across distributed nodes. This security flaw represents a critical authorization bypass issue that stems from improper handling of resource identification and access control mechanisms within the system's user management framework. The vulnerability specifically impacts versions prior to 4.0.0, where the platform's resource naming conventions create ambiguity between numeric identifiers and user-defined names, leading to potential privilege escalation attacks.
The technical flaw manifests when users create resources using integer-based names, creating a direct mapping issue between resource identifiers and user credentials. This occurs because the system fails to properly distinguish between numeric resource IDs and user identifiers during access control checks, particularly in scenarios where user permissions are defined by either username or user ID. When a legitimate user with ID 13 is granted permission to execute algorithms, an attacker can exploit this by creating a resource with the name '13', thereby gaining unauthorized access to execute algorithms that should be restricted to the legitimate user. This represents a classic case of identifier confusion that violates fundamental access control principles and creates a path for unauthorized privilege escalation.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it fundamentally undermines the trust model that federated learning platforms rely upon for secure collaboration. In a privacy-preserving federated learning environment, where multiple organizations share computational resources while keeping their data isolated, this flaw could enable malicious actors to execute unauthorized algorithms on protected nodes, potentially compromising sensitive data processing workflows. The vulnerability's scope suggests that similar issues may exist throughout the codebase where resource IDs and names are not properly validated, creating a potential attack surface that could be exploited across multiple system components. This type of vulnerability aligns with CWE-284, which addresses improper access control, and represents a specific instance of how identifier confusion can lead to authorization bypass attacks.
The remediation approach recommended for CVE-2023-28635 focuses on implementing strict validation of resource naming conventions during creation and modification operations. The solution requires ensuring that resource names always begin with a character rather than a numeric value, effectively eliminating the potential for identifier collisions between user IDs and resource names. This approach directly addresses the root cause by establishing clear boundaries between different identifier types within the system's resource management layer. The patch implemented in version 4.0.0 demonstrates a defensive programming approach that prevents the problematic naming patterns while maintaining system functionality. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques and could potentially be leveraged in combination with other attack vectors to establish persistent access within federated learning environments. The fix aligns with security best practices for access control implementation and reinforces the principle of least privilege that is essential for maintaining the integrity of privacy-preserving systems. Organizations using vantage6 should prioritize upgrading to version 4.0.0 or later to mitigate this vulnerability and ensure that their federated learning infrastructure maintains proper access controls against unauthorized resource access.