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Unauthenticated control plane denial of service attack due to stack exhaustion

High
howardjohn published GHSA-8w5h-qr4r-2h6g Mar 10, 2022

Package

docker Istio (Docker)

Affected versions

<1.13.2

Patched versions

1.11.8,1.12.5.1.13.2

Description

Impact

The Istio control plane, istiod, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted or oversized message which results in the control plane crashing when the Kubernetes validating or mutating webhook service is exposed publicly. This endpoint is served over TLS port 15017, but does not require any authentication from the attacker.

For simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially external istiod topologies, this port is exposed over the public internet.

Patches

  • Istio 1.13.2 and above
  • Istio 1.12.5 and above
  • Istio 1.11.8 and above

Workarounds

Disable access to a validating webhook that is exposed to the public internet or restrict the set of IP addresses that can query it to a set of known, trusted entities.

References

golang/go#51112

For more information

If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com

Severity

High

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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2022-24726

Weaknesses

No CWEs

Credits