===================================================================                                  CERT-Renater

                       Note d'Information No. 2022/VULN399

_____________________________________________________________________

DATE                : 25/10/2022

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running flux2 (Go) versions prior to
                         0.35.0,
                      helm-controller (Go) versions prior to 0.24.0,
          image-automation-controller (Go) versions prior to 0.26.0,
          image-reflector-controller (Go) versions prior to 0.22.0,
          kustomize-controller (Go) versions prior to 0.29.0,
          notification-controller (Go)) versions prior to 0.27.0,
          source-controller (Go) versions prior to 0.30.0.

====================================================================https://github.com/fluxcd/flux2/security/advisories/GHSA-f4p5-x4vc-mh4v
_____________________________________________________________________

Improper use of metav1.Duration allows for Denial of Service
Moderate	hiddeco published GHSA-f4p5-x4vc-mh4v

Package                 Affected versions            Patched versions
  github.com/fluxcd/flux2 (Go)   < v0.35.0 >= v0.1.0     v0.35.0

  github.com/fluxcd/helm-controller (Go)   < v0.24.0 >= v0.0.1-alpha-1
    v0.24.0

  github.com/fluxcd/image-automation-controller (Go)
< v0.26.0 >= v0.1.0        v0.26.0

  github.com/fluxcd/image-reflector-controller (Go)
< v0.22.0 >= v0.1.0        v0.22.0

  github.com/fluxcd/kustomize-controller (Go)
< v0.29.0 >= v0.0.1-alpha-1      v0.29.0

  github.com/fluxcd/notification-controller (Go)
< v0.27.0 >= v0.0.1-alpha-1      v0.27.0

  github.com/fluxcd/source-controller (Go)   < v0.30.0 >= v0.0.1-alpha-1
v0.30.0


Description
Flux controllers within the affected versions range are vulnerable
to a denial of service attack. Users that have permissions to change
Flux’s objects, either through a Flux source or directly within a
cluster, can provide invalid data to fields .spec.interval or
.spec.timeout (and structured variations of these fields), causing
the entire object type to stop being processed.

The issue has two root causes: a) the Kubernetes type metav1.Duration
not being fully compatible with the Go type time.Duration as
explained on upstream report; b) lack of validation within Flux to
restrict allowed values.


Workarounds
Admission controllers can be employed to restrict the values that can
be used for fields .spec.interval and .spec.timeout, however upgrading
to the latest versions is still the recommended mitigation.


Credits
This issue was reported by Alexander Block (@codablock) through the
Flux security mailing list (as recommended).

For more information
If you have any questions or comments about this advisory:

Open an issue in any of the affected repositories.
Contact us at the CNCF Flux channel.


References
kubernetes/apimachinery#131

Severity
Moderate

5.0/ 10

CVSS base metrics

Attack vector
Network

Attack complexity
Low

Privileges required
Low

User interaction
None

Scope
Changed

Confidentiality
None

Integrity
None

Availability
Low

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

CVE ID
CVE-2022-39272

Weaknesses
CWE-20

Credits
@codablock codablock


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