CVE-2015-5987 in F9K1102
Summary
by MITRE
Belkin F9K1102 2 devices with firmware 2.10.17 use an improper algorithm for selecting the ID value in the header of a DNS query, which makes it easier for remote attackers to spoof responses by predicting this value.
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Analysis
by VulDB Data Team • 11/08/2024
The vulnerability identified as CVE-2015-5987 affects Belkin F9K1102 wireless routers running firmware version 2.10.17 and potentially other similar devices. This issue resides in the DNS query processing mechanism where the device employs an inadequate algorithm for generating identification values in DNS query headers. The flaw represents a significant security weakness that directly impacts the integrity of DNS resolution processes and exposes the network to sophisticated spoofing attacks.
The technical implementation of this vulnerability stems from the predictable nature of the ID value generation algorithm used in DNS queries sent by the affected Belkin devices. When a router processes DNS requests, it assigns identification numbers to each query packet in the DNS header. The improper algorithm used in this specific firmware version produces ID values that follow patterns or exhibit statistical predictability, making it feasible for malicious actors to anticipate these values. This weakness specifically aligns with CWE-330, which addresses the use of insufficiently random values in security contexts, and demonstrates how poor random number generation can compromise network security protocols.
The operational impact of this vulnerability extends beyond simple DNS spoofing capabilities, as it creates opportunities for broader network compromise and man-in-the-middle attacks. Remote attackers can exploit this weakness by monitoring DNS traffic and predicting the identification values used by the router, subsequently injecting false DNS responses into the network. This allows adversaries to redirect users to malicious websites, intercept sensitive communications, or conduct various forms of network disruption attacks. The vulnerability particularly affects the DNS security model by undermining the authentication mechanisms that rely on the uniqueness of query IDs to validate response legitimacy.
Mitigation strategies for CVE-2015-5987 should prioritize firmware updates from Belkin, as the manufacturer likely released patches addressing the predictable ID generation algorithm. Network administrators should also implement additional protective measures including DNSSEC deployment, which provides cryptographic authentication of DNS data, and network monitoring to detect anomalous DNS traffic patterns. The implementation of DNS query ID randomization at the network level can serve as an additional defensive layer, though this approach may not fully address the root cause within the affected devices. Organizations should also consider network segmentation and access control measures to limit the potential impact of successful DNS spoofing attempts. This vulnerability demonstrates the critical importance of proper entropy in network security protocols and aligns with ATT&CK technique T1071.004 for DNS tunneling and spoofing activities, highlighting the broader implications of weak cryptographic foundations in network infrastructure devices.