Improper Object Attribute Control in Ash Framework

Compliance Impact

This vulnerability allows unauthorized modification of private action arguments that can control authorization, identity, or record ownership, potentially leading to integrity violations or privilege escalation.

Such unauthorized access and manipulation of sensitive data or control parameters could negatively impact compliance with standards and regulations like GDPR or HIPAA, which require strict controls over data integrity, access, and authorization.

However, the provided information does not explicitly state the direct impact on compliance with these standards.

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Executive Summary

This vulnerability exists in the Ash framework versions 3.0.0 to before 3.29.3 and involves improper control over private action arguments. These private arguments, which are intended to be set only by trusted server-side code, can be manipulated by user input due to incomplete filtering.

Specifically, when a changeset is built from user-supplied parameters, Ash filters out private arguments only if the parameter key is an atom. However, if the key is a binary (string), which is common in user input, the private argument is not filtered out and can be set by the user. In atomic or bulk update paths, private arguments are never stripped regardless of key type.

As a result, an attacker can inject values for private arguments that should be controlled internally, potentially leading to unauthorized modifications.

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Impact Analysis

Exploiting this vulnerability allows an attacker to inject values into private action arguments that are meant to be controlled only by trusted server-side code.

Depending on how these private arguments are used in the application—for example, if they control authorization, identity, or record ownership—this can lead to integrity violations or privilege escalation.

• Integrity violation: unauthorized modification of data or state.
• Privilege escalation: gaining higher access rights than intended.

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Mitigation Strategies

To mitigate this vulnerability, you should upgrade the Ash framework to version 3.29.3 or later, where the issue has been fixed.

The fix ensures that private action arguments declared with public?: false cannot be set from user input, whether the parameters are string-keyed or atom-keyed.

Additionally, review your application code to ensure that private arguments are not exposed or modifiable from untrusted sources, especially in changeset creation and atomic or bulk update paths.

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Detection Guidance

This vulnerability involves improper filtering of private action arguments in the Ash framework, allowing user input to set values that should be controlled only by server-side code.

To detect exploitation attempts on your system, you should monitor requests that submit parameters to Ash actions, especially those that include keys corresponding to private arguments (declared with public?: false). Look for parameters sent as strings that match private argument names.

Since the vulnerability is related to user-supplied parameters bypassing filtering, you can use logging or network monitoring tools to capture and inspect HTTP request payloads for suspicious parameters.

• Use network packet capture tools like tcpdump or Wireshark to capture traffic to your Ash-based application and filter for POST or PUT requests containing JSON or form data with keys matching private argument names.
• On the server, enable detailed request logging to capture parameter maps submitted to Ash actions.
• Use grep or similar tools on logs to search for occurrences of private argument names in user-supplied parameters, for example: grep -i 'private_argument_name' /path/to/request_logs.log
• If you have access to the application code or database, audit changesets or records for unexpected values in fields controlled by private arguments, which may indicate exploitation.

There are no specific commands provided in the resources for automated detection, so detection relies on monitoring and analyzing input parameters and logs for suspicious private argument usage.

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