CVE-2017-6552 in 3 Sagemcom
Summary
by MITRE
Livebox 3 Sagemcom SG30_sip-fr-5.15.8.1 devices have an insufficiently large default value for the maximum IPv6 routing table size: it can be filled within minutes. An attacker can exploit this issue to render the affected system unresponsive, resulting in a denial-of-service condition for telephone, Internet, and TV services.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/02/2024
The CVE-2017-6552 vulnerability affects Livebox 3 Sagemcom devices running firmware version SG30_sip-fr-5.15.8.1, representing a critical denial-of-service weakness in IPv6 routing table management. This vulnerability stems from an inadequately configured default value for the maximum IPv6 routing table size, which creates a predictable and exploitable condition that allows attackers to rapidly consume available routing table resources. The flaw specifically targets the IPv6 routing table implementation within the device's network stack, where the default configuration fails to provide sufficient protection against resource exhaustion attacks. The vulnerability is particularly concerning because it directly impacts the core network functionality of the device, affecting telephone, internet, and television services simultaneously. The issue demonstrates a fundamental flaw in resource management design where the system does not adequately implement rate limiting or resource allocation controls to prevent malicious actors from overwhelming the routing table capacity.
The technical exploitation of this vulnerability occurs through the deliberate filling of the IPv6 routing table with malicious entries, allowing an attacker to consume available routing table slots within minutes of initiating the attack. This process typically involves sending crafted IPv6 packets or routing updates that create entries in the routing table, eventually exhausting the allocated space. The default configuration of the routing table size is insufficient to handle either legitimate traffic spikes or malicious resource exhaustion attempts, creating a window of opportunity for attackers to disrupt service availability. The vulnerability is classified as a resource exhaustion issue that aligns with CWE-400, which covers improper resource management leading to denial-of-service conditions. The attack vector specifically targets the device's IPv6 processing capabilities, where the routing table management lacks adequate bounds checking or resource limiting mechanisms that would prevent such rapid consumption of available table entries.
The operational impact of CVE-2017-6552 extends beyond simple service disruption to create a comprehensive network availability problem that affects multiple service types simultaneously. When the routing table becomes full, the device cannot properly forward IPv6 packets, resulting in complete service interruption for telephone, internet, and television services that rely on the affected network infrastructure. The vulnerability creates a cascading effect where the device becomes unresponsive to legitimate network traffic, effectively blocking all communication through the affected routing table. This disruption occurs without requiring authentication or specialized access privileges, making the attack surface particularly broad and the impact severe. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network disruption attacks targeting routing table manipulation. The rapid exploitation time frame of minutes indicates that the vulnerability provides a direct path to compromise the device's network functionality without requiring extended reconnaissance or complex attack chains.
Mitigation strategies for this vulnerability should focus on both immediate device-level fixes and long-term architectural improvements to prevent resource exhaustion conditions. Network administrators should consider implementing firmware updates from Sagemcom that address the routing table size configuration and introduce proper rate limiting mechanisms. Additionally, implementing network segmentation and access controls can help limit the impact of potential exploitation attempts by restricting unauthorized access to routing table manipulation capabilities. The vulnerability highlights the importance of proper resource allocation and bounds checking in network device implementations, particularly in critical infrastructure components like routing tables. Organizations should also implement monitoring solutions to detect unusual routing table activity patterns that might indicate exploitation attempts. The issue demonstrates the necessity of following security best practices such as those outlined in the NIST Cybersecurity Framework, specifically focusing on protecting against resource exhaustion attacks and implementing robust network device configuration management. Regular security assessments and vulnerability scanning should include checks for similar resource management flaws in network infrastructure devices to prevent similar vulnerabilities from remaining undetected in production environments.