CVE-2023-27530: Rack Denial of Service Vulnerability
HIGHCVE-2023-27530 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Rack libraries in the RubyGems ecosystem. The issue involves rack has possible dos vulnerability in multipart mime parsing. Remediation is available by upgrading affected packages to version 2.0.9.3, 2.1.4.3, 2.2.6.3, 3.0.4.2.
CVE-2023-27530 at a Glance
Security Impact
CVSS: 7.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
How to Fix CVE-2023-27530
To remediate this vulnerability, upgrade all affected Rack dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade rack to 2.0.9.3Upgrade rack to 2.1.4.3Upgrade rack to 2.2.6.3Upgrade rack to 3.0.4.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for rackHow to Check if You Are Affected
To determine whether your application is affected by CVE-2023-27530, inspect your project dependencies for Rack:
inspect dependencies for rackAnalyze the terminal output to locate any version of Rack in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.9.3), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Rack, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2023-27530 Affected Rack Versions
4 component(s)References
Frequently Asked Questions
What is CVE-2023-27530?
Which Rack versions are affected?
What version fixes CVE-2023-27530?
Is rack affected?
What is the CVSS score of CVE-2023-27530?
What CWE is associated with CVE-2023-27530?
How can I check RubyGems dependencies for CVE-2023-27530?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-3h57-hmj3-gj3p",
"modified" : "2025-02-13T18:41:56Z",
"published" : "2023-03-08T17:20:04Z",
"aliases" : [ "CVE-2023-27530" ],
"summary" : "Rack has possible DoS Vulnerability in Multipart MIME parsing",
"details" : "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.\n\nVersions Affected: All. Not affected: None Fixed Versions: 3.0.4.2, 2.2.6.3, 2.1.4.3, 2.0.9.3\n\n# Impact\nThe 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.\n\nAll users running an affected release should either upgrade or use one of the workarounds immediately.\n\n# Workarounds\nA proxy can be configured to limit the POST body size which will mitigate this issue.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "RubyGems",
"name" : "rack"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "2.0.9.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "RubyGems",
"name" : "rack"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.1.0"
}, {
"fixed" : "2.1.4.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "RubyGems",
"name" : "rack"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.2.0"
}, {
"fixed" : "2.2.6.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "RubyGems",
"name" : "rack"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "3.0.0"
}, {
"fixed" : "3.0.4.2"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-27530"
}, {
"type" : "WEB",
"url" : "https://discuss.rubyonrails.org/t/cve-2023-27530-possible-dos-vulnerability-in-multipart-mime-parsing/82388"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/rack/rack"
}, {
"type" : "WEB",
"url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2023-27530.yml"
}, {
"type" : "WEB",
"url" : "https://lists.debian.org/debian-lts-announce/2023/04/msg00017.html"
}, {
"type" : "WEB",
"url" : "https://security.netapp.com/advisory/ntap-20231208-0015"
}, {
"type" : "WEB",
"url" : "https://www.debian.org/security/2023/dsa-5530"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-400", "CWE-770" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2023-03-08T17:20:04Z",
"nvd_published_at" : "2023-03-10T22:15:00Z"
}
}