Rack up to 2.2.13/3.0.15/3.1.13 Rack::QueryParser resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Rack up to 2.2.13/3.0.15/3.1.13. Affected by this vulnerability is the function Rack::QueryParser. The manipulation leads to resource consumption. This vulnerability is uniquely identified as CVE-2025-46727. The attack is possible to be carried out remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Rack up to 2.2.13/3.0.15/3.1.13 and classified as problematic. This issue affects the function Rack::QueryParser. The manipulation with an unknown input leads to a resource consumption vulnerability. Using CWE to declare the problem leads to CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Impacted is availability. The summary by CVE is:

Rack is a modular Ruby web server interface. Prior to versions 2.2.14, 3.0.16, and 3.1.14, `Rack::QueryParser` parses query strings and `application/x-www-form-urlencoded` bodies into Ruby data structures without imposing any limit on the number of parameters, allowing attackers to send requests with extremely large numbers of parameters. The vulnerability arises because `Rack::QueryParser` iterates over each `&`-separated key-value pair and adds it to a Hash without enforcing an upper bound on the total number of parameters. This allows an attacker to send a single request containing hundreds of thousands (or more) of parameters, which consumes excessive memory and CPU during parsing. An attacker can trigger denial of service by sending specifically crafted HTTP requests, which can cause memory exhaustion or pin CPU resources, stalling or crashing the Rack server. This results in full service disruption until the affected worker is restarted. Versions 2.2.14, 3.0.16, and 3.1.14 fix the issue. Some other mitigations are available. One may use middleware to enforce a maximum query string size or parameter count, or employ a reverse proxy (such as Nginx) to limit request sizes and reject oversized query strings or bodies. Limiting request body sizes and query string lengths at the web server or CDN level is an effective mitigation.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2025-46727 since 04/28/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 236870 (Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 24.10 / 25.04 : Rack vulnerabilities (USN-7507-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.2.14, 3.0.16 or 3.1.14 eliminates this vulnerability. Applying the patch 2bb5263b464b65ba4b648996a579dbd180d2b712 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (236870). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 236870
Nessus Name: Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 24.10 / 25.04 : Rack vulnerabilities (USN-7507-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Rack 2.2.14/3.0.16/3.1.14
Patch: 2bb5263b464b65ba4b648996a579dbd180d2b712

Timelineinfo

04/28/2025 CVE reserved
05/08/2025 +10 days Advisory disclosed
05/08/2025 +0 days VulDB entry created
05/17/2025 +9 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-gjh7-p2fx-99vx
Status: Confirmed

CVE: CVE-2025-46727 (🔒)
GCVE (CVE): GCVE-0-2025-46727
GCVE (VulDB): GCVE-100-307967

Entryinfo

Created: 05/08/2025 07:57
Updated: 05/17/2025 12:00
Changes: 05/08/2025 07:57 (66), 05/17/2025 12:00 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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