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Crash when a cluster is deleted via Cluster Discovery Service

Moderate
mattklein123 published GHSA-9vp2-4cp7-vvxf Feb 22, 2022

Package

envoy (C++)

Affected versions

1.20.0 and newer

Patched versions

1.20.2, 1.21.1

Description

CVSS Score 4.4 AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H, Medium

When a cluster is deleted via Cluster Discovery Service (CDS) all idle connections established to endpoints in that cluster are disconnected. A recursion was introduced in the procedure of disconnecting idle connections that can lead to stack exhaustion and abnormal process termination when a cluster has a large number of idle connections.

Impact

Infinite recursion causes Envoy crash.

Patches

Workarounds

Reduce the maximum number of connections in the cluster circuit breaker, considering that the 8Mb stack (default size on Linux) can only handle disconnecting less than 2K connections.

References

https://blog.envoyproxy.io
https://github.com/envoyproxy/envoy/releases

For more information

Open an issue in Envoy repo
Email us at envoy-security

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
Network
Attack complexity
High
Privileges required
High
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:H/PR:H/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2022-23606

Weaknesses