CVE-2025-36118 Overview
IBM Storage Virtualize versions 8.4, 8.5, 8.7, and 9.1 contain an information disclosure vulnerability in their IKEv1 implementation. Remote attackers can exploit this flaw to obtain sensitive information from device memory by sending crafted Security Association (SA) negotiation requests. This vulnerability is classified as CWE-244 (Improper Clearing of Heap Memory Before Release), indicating that memory is not properly sanitized before being exposed during IKEv1 protocol exchanges.
Critical Impact
Remote unauthenticated attackers can extract sensitive information from device memory via network-based IKEv1 SA negotiation requests, potentially exposing cryptographic keys, credentials, or other confidential data stored in memory.
Affected Products
- IBM Storage Virtualize 8.4.0.0
- IBM Storage Virtualize 8.5.0.0
- IBM Storage Virtualize 8.7.0.0
- IBM Storage Virtualize 9.1.0.0
Discovery Timeline
- 2025-11-17 - CVE-2025-36118 published to NVD
- 2025-12-08 - Last updated in NVD database
Technical Details for CVE-2025-36118
Vulnerability Analysis
This vulnerability resides in the IKEv1 (Internet Key Exchange version 1) implementation within IBM Storage Virtualize. IKEv1 is a critical protocol used to establish Security Associations for IPsec VPN connections. The flaw allows attackers to leverage the SA negotiation process to read uninitialized or improperly cleared heap memory from the affected device.
The vulnerability stems from improper memory handling during the processing of IKEv1 SA negotiation requests. When the device responds to these requests, it may include portions of memory that were not properly cleared, potentially leaking sensitive information that was previously stored in those memory locations.
Root Cause
The root cause is classified under CWE-244: Improper Clearing of Heap Memory Before Release. This occurs when the application fails to properly sanitize heap memory before it is reused or exposed. In the context of IKEv1 negotiation, the protocol implementation allocates memory for processing SA requests and responses, but fails to properly initialize or clear this memory before including it in outbound packets.
This type of vulnerability is particularly concerning in storage virtualization systems where memory may contain:
- Encryption keys and cryptographic material
- Authentication credentials
- Configuration data
- Session tokens and identifiers
Attack Vector
The attack is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by:
- Initiating an IKEv1 SA negotiation with the vulnerable IBM Storage Virtualize system
- Crafting specific SA proposal payloads that trigger the memory disclosure condition
- Analyzing the response packets to extract leaked memory contents
- Repeatedly sending requests to harvest additional memory fragments over time
The vulnerability mechanism involves sending IKEv1 SA negotiation requests that cause the affected device to include uninitialized heap memory in its responses. Since IKEv1 uses UDP port 500 for key exchange, attackers can target this port to initiate the attack. The leaked memory contents vary based on previous operations performed by the system, making each disclosure potentially contain different sensitive data.
Detection Methods for CVE-2025-36118
Indicators of Compromise
- Unusual volume of IKEv1 SA negotiation attempts from external or unexpected sources
- Repeated IKEv1 connection attempts from the same source that fail to establish complete VPN tunnels
- Abnormal IKEv1 packet sizes in response messages that may indicate memory leakage
- Network traffic analysis showing incomplete or malformed IKEv1 negotiations
Detection Strategies
- Monitor UDP port 500 for anomalous IKEv1 traffic patterns and connection attempts
- Implement IDS/IPS rules to detect excessive IKEv1 SA negotiation requests from single sources
- Review IBM Storage Virtualize logs for failed or suspicious VPN connection attempts
- Deploy network traffic analysis to identify unusual response payload sizes in IKEv1 exchanges
Monitoring Recommendations
- Enable detailed logging for IKEv1/IPsec events on IBM Storage Virtualize systems
- Configure alerts for high-frequency IKEv1 negotiation attempts that could indicate exploitation attempts
- Monitor for reconnaissance activity targeting UDP port 500 across storage infrastructure
- Implement network segmentation monitoring to detect lateral movement following potential information disclosure
How to Mitigate CVE-2025-36118
Immediate Actions Required
- Apply the security patch from IBM immediately on all affected Storage Virtualize systems
- Restrict network access to IKEv1 services (UDP port 500) to only trusted IP addresses
- Consider disabling IKEv1 and migrating to IKEv2 if operationally feasible
- Audit network configurations to ensure storage systems are not directly exposed to untrusted networks
Patch Information
IBM has released a security update to address this vulnerability. Administrators should consult the IBM Support Page for detailed patch information and upgrade instructions specific to their Storage Virtualize version. The patch addresses the improper memory clearing issue in the IKEv1 implementation.
Workarounds
- Implement firewall rules to restrict IKEv1 access to only authorized and trusted management networks
- If IKEv1 functionality is not required, disable the service entirely on affected systems
- Deploy network-level access controls using ACLs to limit exposure of UDP port 500
- Consider using alternative VPN solutions until the patch can be applied
# Example firewall rule to restrict IKEv1 access (adjust for your environment)
# Allow IKEv1 only from trusted management network
iptables -A INPUT -p udp --dport 500 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p udp --dport 500 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
