CVE-2018-1851 in WebSphere Application Server Liberty
Summary
by MITRE
IBM WebSphere Application Server Liberty OpenID Connect could allow a remote attacker to execute arbitrary code on the system, caused by improper deserialization. By sending a specially-crafted request to the RP service, an attacker could exploit this vulnerability to execute arbitrary code. IBM X-Force ID: 150999.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-1851 affects IBM WebSphere Application Server Liberty OpenID Connect implementation, representing a critical security flaw that enables remote code execution through improper object deserialization techniques. This vulnerability specifically targets the relying party (RP) service component within the OpenID Connect framework, creating an attack surface that allows malicious actors to compromise systems remotely without requiring authentication credentials.
The technical flaw stems from inadequate validation during the object deserialization process within the Liberty server's OpenID Connect implementation. When the system processes specially crafted requests containing malicious serialized objects, it fails to properly validate or sanitize the input data before attempting to deserialize and execute the contained objects. This weakness directly maps to CWE-502, which categorizes deserialization of untrusted data as a significant security risk that can lead to remote code execution when objects are instantiated from unverified source material. The vulnerability exploits the inherent trust model within the deserialization mechanism, where the system assumes that incoming serialized objects are safe and legitimate.
The operational impact of this vulnerability is severe and far-reaching, as it allows attackers to execute arbitrary code on the target system with the privileges of the running application server process. This remote code execution capability can result in complete system compromise, data exfiltration, privilege escalation, and potential lateral movement within the network infrastructure. Attackers can leverage this vulnerability to establish persistent backdoors, deploy additional malware, or use the compromised system as a launch point for further attacks against other network resources. The attack vector is particularly dangerous because it requires minimal privileges and can be executed entirely through web-based requests, making it highly accessible to threat actors with basic network connectivity.
Organizations affected by this vulnerability should immediately implement multiple layers of mitigation strategies to protect their systems. The primary recommendation involves applying the official IBM security patches and updates released for this vulnerability, which typically include enhanced input validation and secure deserialization practices. Network segmentation and firewall rules should be implemented to restrict access to the OpenID Connect services, while monitoring systems should be deployed to detect suspicious deserialization activities. Additionally, implementing application whitelisting, disabling unnecessary services, and conducting regular security assessments of the Liberty server configuration can significantly reduce the attack surface. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1059.007 for remote code execution and T1210 for exploitation of remote services, making it a critical target for defensive security operations and incident response protocols.