CVE-2015-6849 in NetWorker
Summary
by MITRE
EMC NetWorker before 8.0.4.5, 8.1.x before 8.1.3.6, 8.2.x before 8.2.2.2, and 9.0 before build 407 allows remote attackers to cause a denial of service (process outage) via malformed RPC authentication messages.
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Analysis
by VulDB Data Team • 06/28/2022
The vulnerability identified as CVE-2015-6849 affects EMC NetWorker software across multiple version ranges including 8.0.4.4 and earlier, 8.1.3.5 and earlier, 8.2.2.1 and earlier, and 9.0 build 406 and earlier. This issue represents a significant security weakness that enables remote attackers to execute denial of service attacks against network services. The flaw specifically targets the Remote Procedure Call authentication mechanism within the NetWorker application, which forms a critical component of the software's security architecture and service availability.
The technical implementation of this vulnerability stems from inadequate input validation within the RPC authentication processing subsystem. When malformed authentication messages are received by the NetWorker service, the system fails to properly handle these malformed inputs, leading to process termination or system instability. This behavior aligns with CWE-129, which describes improper validation of input boundaries, and CWE-20, which covers input validation vulnerabilities. The vulnerability operates at the application layer of the network stack, specifically affecting the authentication handshake process that occurs between client and server components.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the availability of critical backup and recovery services. Organizations relying on EMC NetWorker for data protection may experience unexpected outages that could result in extended downtime for backup operations, potentially leading to data loss or recovery failures during critical moments. The remote nature of the attack means that threat actors can exploit this weakness from external networks without requiring local access or credentials, making it particularly dangerous for enterprise environments where backup systems are often accessible over the internet or through unsecured network connections.
From a threat modeling perspective, this vulnerability maps to several ATT&CK techniques including T1499.004 for network denial of service and T1566.001 for spearphishing with social engineering. The attack surface is particularly concerning for organizations that maintain extensive backup infrastructures, as the disruption could cascade to multiple systems that depend on successful backup operations. The vulnerability demonstrates a fundamental weakness in the software's error handling mechanisms, where malformed input causes the system to crash rather than gracefully rejecting the invalid authentication attempt.
Organizations should prioritize immediate patching of affected systems to remediate this vulnerability. The recommended mitigation strategy involves applying the vendor-supplied patches that address the RPC authentication validation issues and implement proper input sanitization. Network segmentation and access controls should be implemented to limit exposure of NetWorker services to untrusted networks. Additionally, monitoring should be enhanced to detect unusual authentication patterns or service disruptions that may indicate exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in other network services and applications within the organization's infrastructure.