CVE-2015-5038 in Connections
Summary
by MITRE
IBM Connections 3.x before 3.0.1.1 CR3, 4.0 before CR4, 4.5 before CR5, and 5.0 before CR3 does not properly detect recursion during XML entity expansion, which allows remote attackers to cause a denial of service (CPU consumption and application crash) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.
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Analysis
by VulDB Data Team • 05/26/2018
The vulnerability identified as CVE-2015-5038 affects IBM Connections versions 3.x before 3.0.1.1 CR3, 4.0 before CR4, 4.5 before CR5, and 5.0 before CR3, representing a critical flaw in XML processing capabilities. This issue constitutes a classic example of an XML External Entity (XXE) vulnerability that specifically targets the recursive entity expansion mechanism within the IBM Connections platform. The flaw allows malicious actors to exploit the system's failure to properly detect and limit recursive XML entity references, creating a scenario where a single crafted XML document can trigger excessive CPU consumption and ultimately lead to application crashes.
The technical implementation of this vulnerability stems from inadequate input validation and parsing controls within the XML processor component of IBM Connections. When processing XML documents containing deeply nested entity references, the system fails to enforce proper recursion limits or depth checks, allowing attackers to construct XML payloads with thousands or millions of nested entity references. This recursive expansion causes the XML parser to consume excessive computational resources as it attempts to resolve each nested reference, leading to a denial of service condition that can bring the entire application to a halt. The vulnerability closely resembles CVE-2003-1564, which established the precedent for XML entity expansion attacks, but specifically targets IBM Connections' XML handling implementation.
The operational impact of CVE-2015-5038 extends beyond simple service disruption to encompass significant business continuity risks for organizations relying on IBM Connections for collaboration and social networking functionalities. Attackers can exploit this vulnerability to consume system resources at an accelerated rate, potentially causing cascading failures that affect multiple users simultaneously. The resource exhaustion can lead to complete application unavailability, requiring system administrators to restart services manually and potentially resulting in data loss or corruption. Organizations using IBM Connections for critical business processes may experience substantial downtime and productivity losses when this vulnerability is exploited, particularly in environments where the platform serves as a central hub for enterprise communication and document sharing.
From a cybersecurity perspective, this vulnerability aligns with CWE-611 (Improper Restriction of XML External Entity Reference) and represents a variant of the broader XXE attack pattern that has been documented in numerous enterprise applications. The attack surface is particularly concerning as it allows remote exploitation without requiring authentication, making it an attractive target for automated scanning and exploitation tools. Security practitioners should note that this vulnerability operates at the application layer and can be effectively mitigated through proper input validation and XML parser configuration. Organizations should implement strict limits on entity expansion depth, disable external entity resolution, and regularly update their IBM Connections installations to prevent exploitation attempts. The remediation process requires careful attention to ensure that security patches do not introduce compatibility issues with existing workflows or integrations within the IBM Connections ecosystem.