CVE-2015-6463 in HART Comm DTM
Summary
by MITRE
CodeWrights HART Comm DTM components, as used with Endress+Hauser FieldCare, allow remote attackers to read arbitrary files, send HTTP requests to intranet servers, or cause a denial of service (CPU and memory consumption) via a longtag XML schema containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.
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Analysis
by VulDB Data Team • 06/19/2018
The vulnerability identified as CVE-2015-6463 represents a critical XML External Entity (XXE) flaw within CodeWrights HART Comm DTM components that are integrated into Endress+Hauser FieldCare software systems. This issue arises from the improper handling of XML schema definitions that contain external entity declarations, creating a pathway for malicious actors to exploit the system through carefully crafted XML payloads. The vulnerability specifically affects industrial automation environments where FieldCare is deployed for field device configuration and maintenance, making it particularly concerning for operational technology infrastructure. The XXE vulnerability stems from the XML parser's failure to adequately validate and sanitize external entity references, allowing attackers to manipulate the parsing process and execute unauthorized operations.
The technical exploitation of this vulnerability occurs through the manipulation of XML tag structures that contain external entity declarations, combined with entity references that trigger unintended system behavior. Attackers can leverage this flaw to perform arbitrary file reads from the system where the DTM components are installed, potentially accessing sensitive configuration files, authentication credentials, or proprietary industrial data. The vulnerability also enables attackers to initiate HTTP requests to internal network servers, effectively allowing them to probe and interact with the internal infrastructure as if they were legitimate system components. This capability significantly expands the attack surface and can lead to further exploitation opportunities within the industrial network environment.
The operational impact of CVE-2015-6463 extends beyond simple data exfiltration, as it can also be weaponized to cause denial of service conditions that consume excessive CPU and memory resources. This resource exhaustion can lead to system instability, application crashes, or complete service disruption within industrial control systems. The vulnerability affects the core functionality of FieldCare software, which is essential for maintaining and configuring field devices in industrial environments, potentially compromising the reliability and safety of critical infrastructure operations. The combination of information disclosure, remote code execution potential, and denial of service capabilities makes this vulnerability particularly dangerous in operational technology environments where system uptime and data integrity are paramount.
Mitigation strategies for this vulnerability should focus on implementing proper XML parser configuration to disable external entity processing and DTD (Document Type Definition) resolution. Organizations should apply vendor-provided patches or updates that address the XXE handling within the HART Comm DTM components, while also implementing network segmentation to limit access to FieldCare systems. The implementation of web application firewalls and XML validation mechanisms can provide additional layers of protection against malformed XML requests. Security monitoring should be enhanced to detect unusual patterns of HTTP requests or file access attempts that may indicate exploitation attempts. According to CWE standards, this vulnerability maps to CWE-611, which specifically addresses Improper Restriction of XML External Entity Reference, and aligns with ATT&CK techniques related to initial access through remote services and privilege escalation via data manipulation. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar XXE vulnerabilities across the industrial control system infrastructure.