CVE-2020-25926 in NicheStack TCPIP
Summary
by MITRE • 08/19/2021
The DNS client in InterNiche NicheStack TCP/IP 4.0.1 is affected by: Insufficient entropy in the DNS transaction id. The impact is: DNS cache poisoning (remote). The component is: dns_query_type(). The attack vector is: a specific DNS response packet.
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Analysis
by VulDB Data Team • 08/21/2021
The vulnerability identified as CVE-2020-25926 resides within the DNS client implementation of InterNiche NicheStack TCP/IP version 4.0.1, representing a critical security flaw that undermines the integrity of DNS resolution processes. This weakness specifically targets the dns_query_type() function which handles DNS query operations, making it a primary attack surface for malicious actors seeking to compromise network communications. The vulnerability stems from inadequate entropy in the generation of DNS transaction identifiers, which are critical for maintaining the authenticity and integrity of DNS query-response cycles.
The technical flaw manifests when the DNS client generates transaction IDs with insufficient randomness, allowing attackers to predict or guess these identifiers within a reasonable timeframe. This weakness directly violates the fundamental security principles of DNS operations where transaction IDs serve as a crucial mechanism to correlate queries with their corresponding responses and prevent unauthorized modifications to DNS cache entries. According to CWE-338, this represents a weakness in entropy generation, specifically targeting the predictability of cryptographic random number generators used in network protocols. The vulnerability enables a sophisticated attack pattern where an adversary can craft malicious DNS response packets that match the expected transaction ID, thereby fooling the client into accepting poisoned DNS records.
The operational impact of this vulnerability extends beyond simple network disruption to encompass full-scale DNS cache poisoning attacks that can redirect network traffic to malicious destinations. When successful, attackers can manipulate DNS resolution results to redirect users to fraudulent websites, intercept communications, or facilitate further attacks within the network infrastructure. This vulnerability operates under the MITRE ATT&CK framework category of T1071.004 for Application Layer Protocol: DNS, where adversaries exploit weaknesses in DNS implementations to achieve their objectives. The remote nature of the attack means that malicious actors can exploit this vulnerability from outside the network perimeter, making it particularly dangerous for organizations that rely on external DNS resolution services.
Mitigation strategies for CVE-2020-25926 should prioritize immediate patching of affected InterNiche NicheStack implementations to ensure proper entropy generation in DNS transaction ID creation. Organizations should also implement additional network security measures including DNS response rate limiting, DNS transaction ID randomization, and monitoring for suspicious DNS activity patterns that could indicate cache poisoning attempts. Network administrators should consider implementing DNS security extensions such as DNSSEC to provide additional layers of protection against these types of attacks. The vulnerability highlights the critical importance of proper random number generation in network security protocols and serves as a reminder that even seemingly minor implementation flaws can lead to significant security breaches. Organizations using InterNiche NicheStack should conduct comprehensive vulnerability assessments to identify all instances of the affected software and ensure complete remediation across their network infrastructure.