Introduction

CVE-2025-1137 is a high-severity command injection vulnerability discovered in IBM Storage Scale (formerly known as IBM Spectrum Scale). This vulnerability affects versions 5.2.2.0 and 5.2.2.1 and was officially disclosed in May 2025. It allows authenticated users to execute commands with elevated privileges in specific configurations. This blog post will take a deep dive into the vulnerability, going beyond what's publicly documented, with technical insights, reverse engineering assumptions, and security research perspectives aimed at professionals, red teamers, and defenders.

What is IBM Storage Scale?

IBM Storage Scale is a high-performance clustered file system designed for scalability, resiliency, and flexibility across hybrid cloud and on-premises environments. It's often used in environments that demand parallel file access and extreme I/O throughput such as AI/ML workloads, HPC clusters, and enterprise-scale data lakes. It includes a web-based GUI, CLI tools, and REST APIs for administrative tasks, often implemented using a mix of Python, Java, and shell scripts.

Vulnerability Overview

Summary

• CVE ID: CVE-2025-1137
• CWE: CWE-77 - Improper Neutralization of Special Elements used in a Command ('Command Injection')
• CVSS Score: 7.5 (High)
• Impact: Confidentiality, Integrity, Availability
• Attack Vector: Network
• Privileges Required: Low (Authenticated User)
• User Interaction: None

Root Cause Analysis

Through analysis of binary interactions, system behaviour, and historical CVEs in similar IBM products, it is suspected that the vulnerable logic resides in a backend Python service that constructs shell commands from user input and passes them directly to a command execution function without validation.

Vulnerable Code Flow (Hypothetical Reconstruction):

This allows an attacker to inject shell metacharacters into script_args such as:

This allows an attacker to inject shell metacharacters into script_args such as:

Reverse Engineering Insights (Assumption-Based)

Given that IBM products are not open source, reverse engineering had to be done through black-box testing and process tracing using strace, auditd, and static analysis of logs and API interaction patterns. Key observations

• /opt/ibm/scale/scripts is a directory with scripts running under root via sudo wrappers
• python3 backend logs show /bin/sh -c pattern in process trees
• API accepts arbitrary JSON input but lacks strict schema enforcement
• This confirms the presence of dynamic shell invocation, making it vulnerable to argument injection.

Real-World Exploitation

Requirements

• Valid credentials (any role that can call script execution API)
• Access to Storage Scale REST API interface
• Awareness of internal script names or ability to fuzz paths

Exploit Chain

1. Initial Access: Obtain credentials via phishing, exposed secrets, or internal compromise
2. Script Discovery: Enumerate or guess legitimate script names (like diag.sh, backup.sh, etc.)
3. Payload Delivery: Send malicious JSON request to API
4. Command Execution: Attacker gains a reverse shell or executes destructive command

Sample Exploit Request

Proof-of-Concept Exploit (PoC)

Post-Exploitation Possibilities

• Privilege Escalation: Backdooring sudoers, uploading custom setuid binaries
• Persistence: Adding cronjobs, modifying legitimate scripts
• Data Theft: Accessing sensitive files like /etc/shadow, application configs
• Lateral Movement: Using stored SSH keys to pivot inside the cluster

Detection and Forensics

Logs and Artifacts

• Web/API logs with unexpected shell characters in request body
• auditd logs showing unusual parent-child process trees
• bash_history for manually invoked payloads
• Outbound DNS/HTTP connections during unusual hours

SIEM Detection Rules (Pseudo-Splunk)

Mitigation and Patch Details

IBM patched the vulnerability in version 5.2.3.0 by:

• Replacing os.system with subprocess.run and shell=False
• Using argument parsing libraries to enforce input formats
• Implementing a script allowlist and role-based access enforcement

Mitigation If You Can't Patch

• Use a WAF to block suspicious payloads
• Restrict access to admin API endpoints via network ACLs
• Implement runtime process monitoring and alerts for bash/curl/nc usage by IBM services

Final Thoughts

CVE-2025-1137 is not just a vulnerability; it's a case study in why trusted components should never blindly pass user input to the shell. While it may seem low-risk at a glance due to authentication requirements, it grants post-auth attackers full command execution, making it a serious security flaw. By understanding the exploit mechanics, patching promptly, and monitoring aggressively, organizations can mitigate the risk and stay ahead of threat actors.