CVE-2015-8265 in E5186 4G LTE Router
Summary
by MITRE
Huawei E5186 4G LTE router with software before V200R001B310D01SP00C00 allows DNS query packets using the static source port, which makes it easier for remote attackers to spoof responses via unspecified vectors.
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Analysis
by VulDB Data Team • 11/11/2024
The Huawei E5186 4G LTE router represents a critical network infrastructure device widely deployed in enterprise and consumer environments for mobile connectivity. This particular vulnerability affects firmware versions prior to V200R001B310D01SP00C00, indicating a significant security gap that persisted across multiple software releases. The device operates as a gateway for mobile data services, handling DNS resolution requests from connected clients while maintaining its own DNS query mechanisms for network operations and configuration updates. The vulnerability manifests in the router's DNS client implementation where it utilizes static source ports for outbound DNS queries, creating predictable communication patterns that adversaries can exploit to manipulate network traffic.
The technical flaw stems from the router's improper handling of DNS query packets, specifically the use of static source ports rather than dynamic port allocation. This design choice fundamentally weakens the security posture by eliminating the randomization that typically protects against DNS spoofing attacks. When DNS queries are sent from predictable source ports, attackers can monitor network traffic and anticipate the port numbers used by the router during DNS resolution. This predictable behavior creates opportunities for man-in-the-middle attacks where malicious actors can inject false DNS responses that appear legitimate to the router, potentially redirecting traffic to malicious destinations or intercepting sensitive communications.
The operational impact of this vulnerability extends beyond simple network disruption to encompass serious data integrity and confidentiality risks. Remote attackers can exploit this weakness to perform DNS cache poisoning attacks, where false DNS records are injected into the router's DNS cache, causing legitimate traffic to be redirected to attacker-controlled servers. This capability enables various malicious activities including phishing attacks, malware distribution, and data exfiltration. The vulnerability is particularly concerning because it affects the router's core network functionality, potentially compromising all devices connected to the network through the affected router. The unspecified vectors mentioned in the CVE description suggest that the attack surface may include multiple exploitation techniques, making the vulnerability more dangerous than initially apparent.
Mitigation strategies for this vulnerability require immediate firmware updates to the affected Huawei E5186 routers, specifically targeting the V200R001B310D01SP00C00 release or later versions that address the DNS query port handling. Network administrators should implement additional defensive measures including DNSSEC deployment to validate DNS responses, network monitoring for unusual DNS traffic patterns, and firewall rules to restrict DNS traffic to trusted sources. Organizations should also consider implementing network segmentation to limit the potential impact of successful attacks and establish robust monitoring procedures to detect unauthorized DNS modifications. The vulnerability aligns with CWE-1031, which addresses security weaknesses in protocols and implementations, and maps to ATT&CK technique T1071.004 for application layer protocol: DNS, highlighting the need for comprehensive network security controls.
The broader implications of this vulnerability demonstrate the critical importance of proper port management in network security implementations. The use of static source ports in DNS queries represents a fundamental security flaw that violates established best practices for network protocol implementation. This vulnerability serves as a reminder that even seemingly minor implementation details in network infrastructure devices can create significant security risks. Organizations should conduct thorough vulnerability assessments of their network infrastructure to identify similar issues in other devices and implement robust security controls including regular firmware updates, network monitoring, and security testing procedures to prevent exploitation of similar vulnerabilities.