CVE-2015-7450

What Is IBM WebSphere Application Server?

IBM WebSphere Application Server (WAS) is a Java EE application server that forms a cornerstone of IBM's enterprise middleware stack. WebSphere is deployed in banking, insurance, government, healthcare, and large enterprise organizations worldwide to run mission-critical Java applications, web services, and transaction processing systems. IBM WebSphere is particularly prevalent in financial services and government — making it a high-value target for attackers seeking access to critical business systems and sensitive data.

WebSphere's administrative infrastructure, SOAP interfaces, RMI/IIOP endpoints, and HTTP management ports accept serialized Java objects — any of which may be exploitable via Java deserialization vulnerabilities if the classpath contains vulnerable libraries.

Overview

CVE-2015-7450 is a critical unauthenticated remote code execution vulnerability in IBM WebSphere Application Server caused by unsafe Java deserialization of objects received via serialized-object interfaces. The root cause is the same as CVE-2015-4852 (Oracle WebLogic): WebSphere included Apache Commons Collections in its classpath, and that library contained gadget chains that could be triggered during deserialization to execute arbitrary OS commands. IBM published a security bulletin in November 2015 and released interim fixes. The vulnerability affects WebSphere Application Server across multiple major versions and extends to IBM products built on the WebSphere platform.

Affected Versions

IBM released interim fixes and fix packs addressing CVE-2015-7450. Consult IBM's security bulletin for specific fix pack version numbers for your installed release.

Technical Details

Root Cause: Apache Commons Collections Deserialization Gadget Chains

CVE-2015-7450 exploits unsafe Java object deserialization (CWE-502) in IBM WebSphere Application Server. The vulnerability follows the same pattern as the broader 2015 Java deserialization epidemic:

1. Gadget chain construction — Apache Commons Collections library (bundled in WebSphere's classpath) contains classes like InvokerTransformer that can be chained together during deserialization to invoke arbitrary Java methods, ultimately calling Runtime.exec() to execute OS commands
2. Payload delivery — an attacker sends a malicious serialized Java object to one of WebSphere's network-accessible endpoints that accepts serialized objects (SOAP/HTTP management interfaces, RMI/IIOP ports, administrative console)
3. Deserialization trigger — WebSphere deserializes the received object, which instantiates the gadget chain classes during the deserialization process
4. Command execution — the gadget chain executes an OS command as the WebSphere service account

The attack requires no authentication — WebSphere's serialized-object interfaces were designed for trusted communication and performed no authentication before deserializing received data.

Breadth of IBM Product Exposure

IBM's bulletin noted that the vulnerability extended beyond WebSphere Application Server to other IBM products using the same underlying WebSphere runtime and Apache Commons Collections dependency, including IBM analytics products, business process management solutions, and infrastructure management products.

Attack Characteristics

Discovery

Gabriel Lawrence and Chris Frohoff of FoxGlove Security published their research on November 6, 2015, demonstrating Apache Commons Collections gadget chain exploitation against WebSphere (among other Java application servers). IBM acknowledged the issue in a security bulletin issued November 26, 2015.

Exploitation Context

• Enterprise Java deserialization epidemic: CVE-2015-7450 is part of the same 2015 Apache Commons Collections deserialization epidemic that affected Oracle WebLogic (CVE-2015-4852), JBoss/WildFly, Jenkins, and OpenNMS — representing a systemic vulnerability in Java enterprise application server design
• Financial services targeting: IBM WebSphere's prevalence in banking and financial services makes CVE-2015-7450 particularly attractive for financially motivated threat actors; compromising a WebSphere instance can provide access to payment processing, account management, and financial transaction systems
• Long exploitation tail: CISA's January 2022 KEV addition confirms exploitation of WebSphere deserialization years after IBM released fixes; enterprise middleware often runs unpatched for extended periods due to change management complexity and application compatibility concerns
• Cryptomining and ransomware: WebSphere deserialization vulnerabilities have been exploited for cryptominer deployment and as an entry point for ransomware operators who then move laterally from the WebSphere server to broader network access
• CISA KEV (2022): Added January 2022

Remediation

1. Apply IBM interim fixes and fix packs — install the IBM-provided fix packs addressing CVE-2015-7450 for your WebSphere version. Consult IBM's security bulletin for specific fix package identifiers.

2. Restrict WebSphere management ports — firewall WebSphere's SOAP connector port (default 8880), RMI/IIOP ports (2809, 9100), and administrative console (9043/9443) to allow access only from authorized management hosts. These ports should never be internet-accessible.

3. Apply JEP 290 deserialization filters — configure JVM-level deserialization class filters to reject unexpected class types before instantiation. IBM provides guidance for configuring serialization filters for WebSphere.

4. Upgrade Apache Commons Collections — update the Commons Collections library in WebSphere's classpath to version 3.2.2 or later (which includes serialization safeguards).

5. Monitor for post-exploitation indicators — watch for unexpected child processes from the WebSphere JVM, new scheduled tasks or cron jobs, outbound connections to unexpected destinations, and cryptominer processes consuming CPU resources.