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Unchecked fieldpath index in Composition's patches can lead to arbitrary memory allocation

Moderate
turkenh published GHSA-v829-x6hh-cqfq Mar 9, 2023

Package

gomod github.com/crossplane/crossplane (Go)

Affected versions

<= 1.11.1, <= 1.10.2, <= 1.9.1

Patched versions

1.11.2, 1.10.3, 1.9.2

Description

Summary

Fuzz testing, by Ada Logics and sponsored by the CNCF, identified a vulnerability in the fieldpath package from crossplane/crossplane-runtime that an already highly privileged Crossplane user able to create or update Compositions could leverage to cause an out of memory panic in Crossplane.

Details

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, that slice's size will be increased 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.

Workaround

Users can restrict write privileges on Compositions to only admin users as a workaround.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Adjacent
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

CVE ID

CVE-2023-27484

Weaknesses

Credits