CVE-2016-5003 in Archiva
Summary
by MITRE
The Apache XML-RPC (aka ws-xmlrpc) library 3.1.3, as used in Apache Archiva, allows remote attackers to execute arbitrary code via a crafted serialized Java object in an <ex:serializable> element.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/09/2022
The Apache XML-RPC library version 3.1.3 contains a critical vulnerability that enables remote code execution through improper handling of serialized Java objects. This flaw exists within the ws-xmlrpc component that is widely utilized in enterprise applications including Apache Archiva, making it a significant concern for organizations relying on these systems. The vulnerability stems from insufficient validation of serialized object data within the XML-RPC processing pipeline, specifically when handling the <ex:serializable> element that contains Java serialized objects. Attackers can craft malicious XML requests containing serialized Java objects that, when processed by the vulnerable library, trigger arbitrary code execution on the target system. This represents a classic deserialization vulnerability where untrusted input is directly deserialized without proper security checks or sandboxing mechanisms.
The technical exploitation of CVE-2016-5003 follows a well-established pattern that aligns with CWE-502, which describes deserialization of untrusted data as a critical security weakness. The vulnerability allows attackers to bypass normal access controls and execute arbitrary commands with the privileges of the affected application. When the XML-RPC library processes the malicious serialized object contained within the <ex:serializable> element, it performs deserialization without adequate validation or sanitization of the input data. This creates a pathway for attackers to inject malicious Java classes that can perform actions such as executing system commands, accessing sensitive files, or establishing reverse shells. The attack vector is particularly dangerous because it requires no authentication and can be executed through standard XML-RPC communication channels, making it accessible to any attacker who can send requests to the vulnerable service.
The operational impact of this vulnerability extends beyond immediate code execution capabilities to encompass broader security implications for affected systems. Organizations using Apache Archiva or other applications built on the vulnerable XML-RPC library face potential complete system compromise, data exfiltration, and lateral movement opportunities for attackers. The vulnerability affects not just individual applications but entire infrastructures that rely on XML-RPC communication protocols, particularly those in enterprise environments where such libraries are commonly deployed. Systems running vulnerable versions may experience unauthorized access to sensitive data, modification of critical application components, and potential use as a foothold for further attacks within the network. The attack surface is particularly large given that XML-RPC is used across multiple platforms and applications, making this vulnerability particularly dangerous for organizations with distributed systems.
Mitigation strategies for CVE-2016-5003 should focus on immediate patching of affected systems and implementation of additional security controls. Organizations must upgrade to Apache XML-RPC library versions that address this vulnerability, typically versions 3.1.4 or later, which include proper input validation and deserialization safeguards. Network segmentation and firewall rules should be implemented to restrict access to XML-RPC endpoints where possible, limiting exposure to trusted networks only. Additional protective measures include implementing application-level firewalls, monitoring for unusual XML-RPC traffic patterns, and conducting regular security assessments of XML-RPC implementations. The remediation process should also include comprehensive testing to ensure that patches do not introduce compatibility issues with existing applications. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for command and scripting interpreter and T1105 for remote file execution, making it a critical target for defensive measures and incident response planning. Organizations should also consider implementing runtime application self-protection mechanisms and regular security audits to prevent similar vulnerabilities from being introduced in the future.