REDHAT-BUG-2398167: Medium severity Rack Rack vulnerability

Published Sep 25, 2025
·
Updated

Rack is a modular Ruby web server interface. Prior to version 2.2.18, Rack::QueryParser enforces its paramslimit only for parameters separated by &, while still splitting on both & and ;. As a result, attackers could use ; separators to bypass the parameter count limit and submit more parameters than intended. Applications or middleware that directly invoke Rack::QueryParser with its default configuration (no explicit delimiter) could be exposed to increased CPU and memory consumption. This can be abused as a limited denial-of-service vector. This issue has been patched in version 2.2.18.

Affected Software

1 affected component
Rack Rack<2.2.18

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Rack::QueryParser to a version that resolves this vulnerability.

    Fixed in 2.2.18

Event History

Sep 25, 2025
Data Sourced
via Red Hat·03:02 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2398167?

The severity of REDHAT-BUG-2398167 is considered critical due to the potential for parameter count bypass by attackers.

2

How do I fix REDHAT-BUG-2398167?

To fix REDHAT-BUG-2398167, upgrade Rack to version 2.2.18 or later where the issue has been addressed.

3

What is the nature of the vulnerability in REDHAT-BUG-2398167?

The vulnerability in REDHAT-BUG-2398167 involves improper enforcement of parameter limits in Rack::QueryParser, allowing attackers to bypass limits by using semicolons.

4

What versions of Rack are affected by REDHAT-BUG-2398167?

Rack versions prior to 2.2.18 are affected by REDHAT-BUG-2398167.

5

Can REDHAT-BUG-2398167 lead to other attacks besides parameter count bypass?

Yes, REDHAT-BUG-2398167 can potentially lead to denial of service or other injection attacks due to excessive parameters being processed.

Contact

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