CVE-2023-27484 Unchecked fieldpath index in Composition's patches can lead to arbitrary memory allocation in crossplane

2023-03-0920:22:48

CWE-400

CWE-20

GitHub_M

www.cve.org

cve-2023-27484

composition's patches

memory allocation

crossplane

kubernetes controllers

arbitrary index

excessive memory usage

oom-killed

privileged user

upgrade

write privileges

admin users

CVSS3

6.2

Attack Vector

ADJACENT

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

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

EPSS

0.001

Percentile

31.6%

JSON

crossplane-runtime is a set of go libraries used to build Kubernetes controllers in Crossplane and its related stacks. In affected versions an already highly privileged user able to create or update Compositions can specify an arbitrarily high index in a patch’s ToFieldPath, which could lead to excessive memory usage once such Composition is selected for a Composite resource. Compositions allow users to specify patches inserting elements into arrays at an arbitrary index. When a Composition is selected for a Composite Resource, patches are evaluated and if a specified index is greater than the current size of the target slice, Crossplane will grow that slice up to the specified index, which could lead to an excessive amount of memory usage and therefore the Pod being OOM-Killed. The index is already capped to the maximum value for a uint32 (4294967295) when parsed, but that is still an unnecessarily large value. This issue has been addressed in versions 1.11.2, 1.10.3, and 1.9.2. Users are advised to upgrade. Users unable to upgrade can restrict write privileges on Compositions to only admin users as a workaround.

CNA Affected

[
  {
    "vendor": "crossplane",
    "product": "crossplane",
    "versions": [
      {
        "version": "< 1.9.2",
        "status": "affected"
      },
      {
        "version": ">= 1.10.0, < 1.10.3",
        "status": "affected"
      },
      {
        "version": ">= 1.11.0, < 1.11.2",
        "status": "affected"
      }
    ]
  }
]