CVE-2022-30122

There is a possible denial of service vulnerability in the multipart parsing component of Rack. This vulnerability has been assigned the CVE identifier CVE-2022-30122.

Versions Affected: >= 1.2
Not affected: < 1.2
Fixed Versions: 2.0.9.1, 2.1.4.1, 2.2.3.1

Workarounds

There are no feasible workarounds for this issue.

Carefully crafted multipart POST requests can cause Rack's multipart parser to take much longer than expected, leading to a possible denial of service vulnerability.

Impacted code will use Rack's multipart parser to parse multipart posts. This includes directly using the multipart parser like this:

params = Rack::Multipart.parse_multipart(env)

But it also includes reading POST data from a Rack request object like this:

p request.POST # read POST data
p request.params # reads both query params and POST data

All users running an affected release should either upgrade or use one of the workarounds immediately.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2022-30122 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.0.9.1, 2.1.4.1, 2.2.3.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2022-30122? CVE-2022-30122 is a high-severity uncontrolled resource consumption vulnerability in rack (rubygems), affecting versions >= 1.2, <= 2.0.9.0. It is fixed in 2.0.9.1, 2.1.4.1, 2.2.3.1. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2022-30122? CVE-2022-30122 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of rack are affected by CVE-2022-30122? rack (rubygems) versions >= 1.2, <= 2.0.9.0 is affected.
4. Is there a fix for CVE-2022-30122? Yes. CVE-2022-30122 is fixed in 2.0.9.1, 2.1.4.1, 2.2.3.1. Upgrade to this version or later.
5. Is CVE-2022-30122 exploitable, and should I be worried? Whether CVE-2022-30122 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2022-30122 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2022-30122?
   • Upgrade rack to 2.0.9.1 or later
   • Upgrade rack to 2.1.4.1 or later
   • Upgrade rack to 2.2.3.1 or later

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