CVE-2011-0887 in Smcd3g-ccr Firmware
Summary
by MITRE
The web management portal on the SMC SMCD3G-CCR (aka Comcast Business Gateway) with firmware before 1.4.0.49.2 uses predictable session IDs based on time values, which makes it easier for remote attackers to hijack sessions via a brute-force attack on the userid cookie.
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Analysis
by VulDB Data Team • 07/13/2024
The vulnerability identified as CVE-2011-0887 affects the SMC SMCD3G-CCR residential gateway device manufactured by Comcast, specifically impacting versions of the device firmware prior to 1.4.0.49.2. This device serves as a critical network access point for residential and small business users, providing both routing and modem functionality while exposing a web management portal for administrative configuration. The web interface represents a significant attack surface as it allows users to configure network settings, manage security policies, and control device operations remotely. The vulnerability stems from the implementation of session management within the web portal, where the system generates session identifiers using predictable time-based algorithms rather than cryptographically secure random number generators.
The technical flaw manifests in the session ID generation mechanism which relies on time values as a primary component for creating unique identifiers for user sessions. This predictable approach violates fundamental security principles for session management and creates a deterministic pattern that attackers can exploit through brute-force techniques. When users authenticate to the web management portal, the system assigns a session ID that incorporates temporal elements such as timestamps or system uptime values. These time-based components, when combined with knowledge of the system's operational parameters, enable attackers to calculate or guess valid session tokens without requiring legitimate credentials. The vulnerability directly maps to CWE-330 Use of Insufficiently Random Values, which specifically addresses the use of weak random number generators in security-critical contexts. Additionally, this weakness enables session hijacking attacks that align with ATT&CK technique T1563.002 for credentials from password managers and broader session management exploitation patterns.
The operational impact of this vulnerability extends beyond simple unauthorized access to the device's administrative interface. Successful exploitation allows remote attackers to completely compromise the gateway device, potentially gaining control over network traffic, modifying firewall rules, changing DNS settings, and accessing sensitive network information. Attackers could leverage this vulnerability to redirect traffic through malicious servers, establish persistent backdoors, or launch further attacks against connected devices within the local network. The predictable session IDs also enable automated attack tools to systematically brute-force valid session tokens, making the exploitation relatively straightforward and scalable. Given that many users access the device management portal from public networks or unsecured connections, the risk of exploitation increases significantly, as attackers can potentially perform these attacks without requiring physical access to the device. The vulnerability particularly affects environments where the device serves as a primary network gateway, as it provides attackers with a foothold for lateral movement and extended network compromise.
Mitigation strategies for this vulnerability involve immediate firmware updates to version 1.4.0.49.2 or later, which should implement proper session ID generation using cryptographically secure random number generators. Network administrators should also consider implementing additional security controls such as restricting access to the management portal to specific IP addresses, enabling multi-factor authentication where available, and monitoring for unusual access patterns or session activity. The device should be configured to use secure session management practices including session timeout mechanisms, secure cookie attributes, and proper session invalidation upon logout. Organizations should also conduct regular vulnerability assessments of network infrastructure devices to identify similar weaknesses in session management implementations. From a defensive perspective, this vulnerability highlights the importance of proper random number generation in security contexts and serves as a reminder that even seemingly simple components like session identifiers require careful security design. The issue also demonstrates the need for continuous security monitoring and prompt patch management across all network infrastructure components, as vulnerabilities in consumer-grade devices often go unnoticed until exploited in the wild.