CVE-2013-6948 in WeMo
Summary
by MITRE
The peerAddresses API in the Belkin WeMo Home Automation firmware before 3949 allows remote attackers to read arbitrary files via an XML document 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 • 08/17/2024
The vulnerability identified as CVE-2013-6948 represents a critical XML External Entity (XXE) flaw within the Belkin WeMo Home Automation firmware versions prior to 3949. This issue resides in the peerAddresses API component which processes XML documents submitted by remote attackers. The vulnerability stems from insufficient input validation and improper XML parsing mechanisms that fail to properly sanitize external entity declarations within XML requests. When an attacker crafts a malicious XML document containing external entity declarations and references, the vulnerable firmware processes these entities without adequate restrictions, leading to unauthorized file access capabilities.
The technical exploitation of this vulnerability follows a classic XXE attack pattern where the attacker leverages XML parsing features to reference external resources through entity declarations. In this case, the peerAddresses API endpoint accepts XML input that contains external entity references pointing to arbitrary files on the device filesystem. The vulnerability is particularly concerning because it allows attackers to read sensitive files from the device's storage without authentication or authorization. The flaw is categorized under CWE-611 as "Improper Restriction of XML External Entity Reference" and aligns with ATT&CK technique T1213.002 for data from information repositories, demonstrating how attackers can extract sensitive information from IoT devices through malformed XML processing.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with potential access to system files, configuration data, and possibly credentials stored within the device's file system. This access could enable further exploitation including privilege escalation, device compromise, or use as a foothold for broader network attacks. The vulnerability affects the core functionality of the WeMo home automation system and could potentially allow attackers to gain insights into device configurations, network topology, or other sensitive operational data. Organizations deploying WeMo devices in residential or commercial environments face significant risk as this vulnerability enables remote exploitation without requiring physical access or advanced privileges.
Mitigation strategies for CVE-2013-6948 should focus on firmware updates to version 3949 or later, which contain proper XML parsing restrictions and external entity handling. Network segmentation and firewall rules should be implemented to limit access to the affected API endpoints, while monitoring systems should be configured to detect unusual XML request patterns. Additionally, implementing XML parser configurations that disable external entity resolution and DTD processing can prevent similar vulnerabilities in other components. Security professionals should also consider conducting vulnerability assessments of other IoT devices within the network to identify similar XXE vulnerabilities that may exist in related systems. The remediation process should include comprehensive testing to ensure that the firmware update does not introduce compatibility issues with existing home automation configurations while maintaining the security improvements necessary to protect against this specific XXE attack vector.