CVE-2023-27530

HIGH

Rack has possible DoS Vulnerability in Multipart MIME parsing

Published March 8, 2023Updated February 13, 2025Source: osv

Summary

There is a possible DoS vulnerability in the Multipart MIME parsing code in Rack. This vulnerability has been assigned the CVE identifier CVE-2023-27530. Versions Affected: All. Not affected: None Fixed Versions: 3.0.4.2, 2.2.6.3, 2.1.4.3, 2.0.9.3 # Impact The Multipart MIME parsing code in Rack limits the number of file parts, but does not limit the total number of parts that can be uploaded. Carefully crafted requests can abuse this and cause multipart parsing to take longer than expected. All users running an affected release should either upgrade or use one of the workarounds immediately. # Workarounds A proxy can be configured to limit the POST body size which will mitigate this issue.

Remediation

Upgrade to the fixed version using your package manager.

Bundler

Update rack to 3.0.4.2 or later

gem install rack -v 3.0.4.2

Bundler

Update rack to 2.1.4.3 or later

gem install rack -v 2.1.4.3

Bundler

Update rack to 2.0.9.3 or later

gem install rack -v 2.0.9.3

Bundler

Update rack to 2.2.6.3 or later

gem install rack -v 2.2.6.3

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (4)

Package	Ecosystem	Affected	Fixed In
rack	rubygems	3.0.0, 3.0.1, 3.0.2, 3.0.3 (+2 more)	3.0.4.2
rack	rubygems	2.1.0, 2.1.1, 2.1.2, 2.1.3 (+3 more)	2.1.4.3
rack	rubygems	0.1.0, 0.2.0, 0.3.0, 0.4.0 (+79 more)	2.0.9.3
rack	rubygems	2.2.0, 2.2.1, 2.2.2, 2.2.3 (+6 more)	2.2.6.3

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CWE-400
Uncontrolled Resource ConsumptionMITRE
CWE-770
Allocation of Resources Without LimitsMITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 7.5 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Frequently Asked Questions

What is CVE-2023-27530?: Rack has possible DoS Vulnerability in Multipart MIME parsing This vulnerability has been assigned a severity rating of HIGH (CVSS score: 7.5/10).
How do I check if my project is affected by CVE-2023-27530?: CVE-2023-27530 affects rack. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2023-27530 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

7.5

High exploitability or significant impact. Prioritize remediation within days.

Also Known As

GHSA-3h57-hmj3-gj3p

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