CVE-2025-27365: IBM MQ Operator DoS Vulnerability

CVE-2025-27365 Overview

CVE-2025-27365 is a Use-After-Free (CWE-416) vulnerability affecting IBM MQ Operator across multiple release channels including LTS, CD, and SC2 versions. The vulnerability allows an authenticated client connecting to an MQ Queue Manager to trigger a SIGSEGV signal in the AMQRMPPA channel process, causing process termination and resulting in a denial of service condition.

This vulnerability impacts enterprise messaging infrastructure deployments running IBM MQ in containerized Kubernetes environments, where the MQ Operator manages Queue Manager instances. Successful exploitation can disrupt critical business messaging operations and communication channels.

Critical Impact

Authenticated attackers can remotely crash the AMQRMPPA channel process through crafted client connections, causing denial of service to IBM MQ Queue Manager deployments in containerized environments.

Affected Products

• IBM MQ Operator LTS 2.0.0 through 2.0.29
• IBM MQ Operator CD 3.0.0, 3.0.1, 3.1.0 through 3.1.3, 3.3.0, 3.4.0, 3.4.1, 3.5.0, 3.5.1
• IBM MQ Operator SC2 3.2.0 through 3.2.10
• IBM Supplied MQ Advanced Container Images (multiple versions from 9.2.x through 9.4.x)

Discovery Timeline

• May 1, 2025 - CVE-2025-27365 published to NVD
• August 25, 2025 - Last updated in NVD database

Technical Details for CVE-2025-27365

Vulnerability Analysis

This vulnerability is classified as a Use-After-Free (CWE-416) memory corruption issue within the AMQRMPPA channel process of IBM MQ. Use-After-Free vulnerabilities occur when a program continues to use a pointer after the memory it references has been deallocated. In the context of IBM MQ, this manifests when a client connection triggers a condition where the channel process attempts to access freed memory, resulting in a SIGSEGV (segmentation fault) signal.

The AMQRMPPA process is the Message Processing Application for receiving channels in IBM MQ. When this process terminates unexpectedly due to the SIGSEGV, any active client connections utilizing that channel are disrupted, effectively creating a denial of service condition. The vulnerability requires network access and low-privilege authentication to exploit, making it accessible to any authenticated MQ client.

Root Cause

The root cause lies in improper memory lifecycle management within the AMQRMPPA channel process. The process fails to properly validate memory references before accessing them during client connection handling. When certain conditions are met during client interaction with the Queue Manager, the process accesses memory that has already been freed, triggering a segmentation fault.

This type of vulnerability typically results from:

• Incorrect ordering of memory deallocation and pointer use
• Missing null checks after memory operations
• Race conditions in multi-threaded environments where one thread frees memory while another still holds a reference

Attack Vector

The attack can be executed remotely over the network by an authenticated client. The attacker needs valid credentials to connect to the MQ Queue Manager but does not require elevated privileges. The exploitation mechanism involves:

1. Establishing a legitimate client connection to the MQ Queue Manager
2. Sending crafted messages or connection requests that trigger the vulnerable code path
3. Causing the AMQRMPPA process to access freed memory, resulting in SIGSEGV
4. The channel process terminates, disconnecting all clients using that channel

The network-based attack vector combined with low-privilege requirements makes this vulnerability particularly concerning for organizations with multiple MQ clients or those allowing connections from less-trusted network segments.

Detection Methods for CVE-2025-27365

Indicators of Compromise

• Unexpected SIGSEGV signals in AMQRMPPA process logs
• Repeated channel process crashes or restarts in Queue Manager error logs
• Unusual client connection patterns followed by channel terminations
• Core dumps generated by AMQRMPPA processes

Detection Strategies

• Monitor IBM MQ error logs for AMQRMPPA process termination events and SIGSEGV signals
• Implement alerting on Queue Manager channel restart frequency anomalies
• Audit client connection logs for patterns preceding channel crashes
• Enable detailed channel event logging to capture connection sequences before crashes

Monitoring Recommendations

• Configure SentinelOne to monitor for process crash events in MQ container workloads
• Set up automated alerts for AMQRMPPA core dump generation
• Track channel availability metrics to detect recurring outages
• Monitor Kubernetes pod restart counts for MQ Operator managed deployments

How to Mitigate CVE-2025-27365

Immediate Actions Required

• Review the IBM Security Support Article for vendor-specific guidance
• Identify all IBM MQ Operator deployments using affected versions
• Prioritize patching for MQ instances exposed to untrusted client connections
• Implement network segmentation to restrict MQ client access to trusted sources only

Patch Information

IBM has released security updates to address this vulnerability. Organizations should upgrade to patched versions of IBM MQ Operator and associated container images as specified in the IBM Security Advisory. The following upgrade paths are recommended:

• MQ Operator LTS: Upgrade from versions 2.0.0-2.0.29 to the latest patched LTS release
• MQ Operator CD: Upgrade from affected 3.x versions to the latest patched CD release
• MQ Operator SC2: Upgrade from versions 3.2.0-3.2.10 to the latest patched SC2 release

Ensure container images are also updated to patched versions as outlined in IBM's advisory.

Workarounds

• Restrict network access to MQ Queue Managers using firewall rules or Kubernetes NetworkPolicies
• Implement strong authentication requirements and limit the number of authorized client connections
• Monitor channel processes closely and configure automatic restart policies to minimize service disruption
• Consider implementing connection rate limiting to reduce the potential impact of exploitation attempts

# Example: Kubernetes NetworkPolicy to restrict MQ access
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: restrict-mq-access
  namespace: mq-namespace
spec:
  podSelector:
    matchLabels:
      app: ibm-mq
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          mq-client-access: "true"
    ports:
    - protocol: TCP
      port: 1414