CVE-2020-8552: K8s.io/apiserver Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-82hx-w2r5-c2wq
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CVSS 5.3
CWE-789 CWE-400 CWE-770
Published
Advisory Summary

CVE-2020-8552 is a MODERATE (CVSS 5.3) denial of service vulnerability (CWE-789: Memory Allocation with Excessive Size Value) affecting K8s.io/apiserver libraries in the Go ecosystem. The issue involves kubernetes api server dos via api requests. Remediation is available by upgrading affected packages to version 0.15.10, 0.16.7, 0.17.3.

CVE-2020-8552 at a Glance

CVE Identifier CVE-2020-8552
GHSA Identifier GHSA-82hx-w2r5-c2wq
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-789: Memory Allocation with Excessive Size Value
Affected Product K8s.io/apiserver
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.3

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:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2020-8552

To remediate this vulnerability, upgrade all affected K8s.io/apiserver dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

k8s.io/apiserver fixed: 0.15.10 
Upgrade k8s.io/apiserver to 0.15.10
k8s.io/apiserver fixed: 0.16.7 
Upgrade k8s.io/apiserver to 0.16.7
k8s.io/apiserver fixed: 0.17.3 
Upgrade k8s.io/apiserver to 0.17.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for k8s.io/apiserver

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-8552, inspect your project dependencies for K8s.io/apiserver:

inspect dependencies for k8s.io/apiserver

Analyze the terminal output to locate any version of K8s.io/apiserver in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.15.10), 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-789: Memory Allocation with Excessive Size Value, where the product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. In K8s.io/apiserver, 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

The Kubernetes API server component in Kubernetes versions prior to 1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via successful API requests.

CVE-2020-8552 Affected K8s.io/apiserver Versions

3 component(s)
Fixed Versions:
0.15.100.16.70.17.3
Product / Package Ecosystem Affected Versions Fixed Version
k8s.io/apiserver
golang/k8s.io/apiserver
Go
< 0.15.10
0.15.10
k8s.io/apiserver
golang/k8s.io/apiserver
Go
≥ 0.16.0
< 0.16.7
0.16.7
k8s.io/apiserver
golang/k8s.io/apiserver
Go
≥ 0.17.0
< 0.17.3
0.17.3

References

NVD — CVE-2020-8552 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-8552
K8s.io/apiserver Source Repository REPOSITORY
https://github.com/kubernetes/kubernetes/issues/89378
K8s.io/apiserver Source Repository REPOSITORY
https://github.com/kubernetes/kubernetes/pull/87669
Security Fix Commit FIX COMMIT
https://github.com/kubernetes/kubernetes/commit/5978856c4c7f10737a11c9540fe60b8475beecbb
groups.google.com/forum/ WEB
https://groups.google.com/forum/#!topic/kubernetes-security-announce/2UOlsba2g0s
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3SOCLOPTSYABTE4CLTSPDIFE6ZZZR4LX
K8s.io/apiserver Security Information SECURITY
https://security.netapp.com/advisory/ntap-20200413-0003

Frequently Asked Questions

What is CVE-2020-8552?
CVE-2020-8552 is a security vulnerability in K8s.io/apiserver involving Kubernetes API Server DoS Via API Requests under CWE-789: Memory Allocation with Excessive Size Value.
Which K8s.io/apiserver versions are affected?
Affected versions include releases prior to 0.15.10, 0.16.7, 0.17.3 across affected packages: k8s.io/apiserver.
What version fixes CVE-2020-8552?
Upgrading to 0.15.10, 0.16.7, 0.17.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is k8s.io/apiserver affected?
Yes, k8s.io/apiserver is affected in releases prior to 0.15.10, 0.16.7, 0.17.3. Upgrade your dependency to 0.15.10, 0.16.7, 0.17.3 or later.
What is the CVSS score of CVE-2020-8552?
CVE-2020-8552 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2020-8552?
CVE-2020-8552 is classified under CWE-789: Memory Allocation with Excessive Size Value (The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.).
How can I check Go dependencies for CVE-2020-8552?
Run the dependency tree command: 'inspect dependencies for k8s.io/apiserver'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-82hx-w2r5-c2wq",
  "modified" : "2023-09-20T22:42:48Z",
  "published" : "2022-02-15T01:57:18Z",
  "aliases" : [ "CVE-2020-8552" ],
  "summary" : "Kubernetes API Server DoS Via API Requests",
  "details" : "The Kubernetes API server component in Kubernetes versions prior to 1.15.9, 1.16.0-1.16.6, and 1.17.0-1.17.2 has been found to be vulnerable to a denial of service attack via successful API requests.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "k8s.io/apiserver"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.15.10"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "k8s.io/apiserver"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.16.0"
      }, {
        "fixed" : "0.16.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "k8s.io/apiserver"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.17.0"
      }, {
        "fixed" : "0.17.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-8552"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubernetes/kubernetes/issues/89378"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubernetes/kubernetes/pull/87669"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubernetes/kubernetes/commit/5978856c4c7f10737a11c9540fe60b8475beecbb"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/forum/#!topic/kubernetes-security-announce/2UOlsba2g0s"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3SOCLOPTSYABTE4CLTSPDIFE6ZZZR4LX"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20200413-0003"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-770", "CWE-789" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-05-06T21:48:16Z",
    "nvd_published_at" : "2020-03-27T15:15:00Z"
  }
}