CVE 6.5 MEDIUM

Apache Storm Client: Anonymous principal assigned on TLS client certificate verification failure_CVE-2026-41081

6.5 / 10
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Description

Improper Handling of TLS Client Authentication Failure Leading to Anonymous Principal Assignment in Apache Storm

Versions Affected: up to 2.8.7

Description: When TLS transport is enabled in Apache Storm without requiring client certificate authentication (the default configuration), the TlsTransportPlugin assigns a fallback principal (CN=ANONYMOUS) if no client certificate is presented or if certificate verification fails. The underlying SSLPeerUnverifiedException is caught and suppressed rather than rejecting the connection.

This fail-open behavior means an unauthenticated client can establish a TLS connection and receive a valid principal identity. If the configured authorizer (e.g., SimpleACLAuthorizer) does not explicitly deny access to CN=ANONYMOUS, this may result in unauthorized access to Storm services. The condition is logged at debug level only, reducing visibility in production.

Impact: Unauthenticated clients may be assigned a principal identity, potentially bypassing authorization in permissive or misconfigured environments.

Mitigation: Users should upgrade to 2.8.7 in which TLS authentication failures are handled in a fail-closed manner.

Users who cannot upgrade immediately should:
- Enable mandatory client certificate authentication (nimbus.thrift.tls.client.auth.required: true)
- Ensure authorization rules explicitly deny access to CN=ANONYMOUS
- Review all ACL configurations for implicit default-allow behavior

Basic Information

ID CVE-2026-41081
Source apache
Published Apr 27, 2026 at 13:10
Modified Apr 27, 2026 at 14:43

Affected Product

Vendor Apache Software Foundation
Product Apache Storm Client
Affected Versions Apache Software Foundation Apache Storm Client 0

CWE Classification

References

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