CVE-2016-3979 in Java AS
Summary
by MITRE
Internet Communication Manager (aka ICMAN or ICM) in SAP JAVA AS 7.4 allows remote attackers to cause a denial of service via a crafted HTTP request, aka SAP Security Note 2256185.
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Analysis
by VulDB Data Team • 09/29/2018
The vulnerability identified as CVE-2016-3979 affects the Internet Communication Manager component within SAP Java Application Server version 7.4, representing a critical denial of service flaw that can be exploited remotely through specially crafted HTTP requests. This vulnerability resides within the ICM module, which serves as the primary communication layer for handling HTTP and HTTPS requests in SAP environments, making it a prime target for attackers seeking to disrupt business operations. The issue stems from insufficient input validation mechanisms within the ICM's HTTP request processing pipeline, allowing malicious actors to construct malformed requests that trigger unexpected behavior in the application server's communication stack.
The technical exploitation of this vulnerability occurs when an attacker crafts HTTP requests containing malformed parameters or unusual request structures that the ICM component fails to properly handle during parsing and processing. When the vulnerable ICM component receives such requests, it encounters a condition that causes the communication manager to either crash, become unresponsive, or enter a state where it cannot process additional legitimate requests. This behavior manifests as a denial of service condition that can severely impact business continuity, particularly in enterprise environments where SAP systems serve as critical backend infrastructure for various business processes. The vulnerability specifically affects the HTTP request handling logic within the ICM, which is designed to manage communication between SAP systems and external clients, making it a fundamental component in the SAP architecture.
From an operational perspective, the impact of CVE-2016-3979 extends beyond simple service interruption, as it can potentially disrupt entire SAP application landscapes that depend on the ICM for communication. Organizations running SAP Java Application Server 7.4 are particularly vulnerable since this version contains the flawed ICM implementation that lacks proper input sanitization and error handling mechanisms. The vulnerability's remote exploitation capability means that attackers do not require local system access or network proximity to cause disruption, making it particularly dangerous in cloud and distributed environments. Security researchers have classified this issue as a significant risk due to its potential for causing widespread service degradation across multiple SAP systems that have not yet been patched, with the attack surface expanding to include any system exposed to HTTP traffic.
The mitigation strategy for this vulnerability centers on applying the official SAP security note 2256185, which provides specific patches and updates to address the ICM processing flaw. Organizations should prioritize immediate deployment of the recommended patches to prevent exploitation, as the vulnerability has been actively targeted by threat actors seeking to disrupt enterprise operations. Network segmentation and access controls should be implemented to limit exposure of vulnerable SAP systems to untrusted networks, while monitoring solutions should be deployed to detect anomalous HTTP request patterns that may indicate attempted exploitation. Additionally, implementing rate limiting and request validation mechanisms at network boundaries can provide defense-in-depth protection against this specific attack vector, though the primary remediation remains the application of SAP's official security updates. This vulnerability aligns with CWE-400, which categorizes it as an Uncontrolled Resource Consumption issue, and maps to ATT&CK technique T1499.004 for Denial of Service through resource exhaustion, emphasizing the need for comprehensive security measures that address both immediate patching requirements and long-term architectural resilience.