CVE-2022-34294 in totd
Summary
by MITRE • 08/15/2022
totd 1.5.3 uses a fixed UDP source port in upstream queries sent to DNS resolvers. This allows DNS cache poisoning because there is not enough entropy to prevent traffic injection attacks.
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Analysis
by VulDB Data Team • 09/11/2022
The vulnerability identified as CVE-2022-34294 affects the totd 1.5.3 DNS resolver implementation where the software employs a fixed UDP source port when initiating queries to upstream DNS resolvers. This flaw represents a significant security weakness that directly impacts the integrity of DNS resolution processes and creates exploitable conditions for cache poisoning attacks. The use of a predetermined source port eliminates the cryptographic entropy typically required to ensure unique transaction identifiers between client and server communications, fundamentally undermining the security assumptions of DNS protocols.
This vulnerability stems from a fundamental design flaw in the DNS resolver's query generation mechanism where the source port remains static across all upstream communications. The fixed port creates predictable transaction patterns that adversaries can exploit to inject malicious responses into DNS caches. The lack of sufficient entropy in the source port selection process violates established security principles for network communication protocols and creates a predictable attack surface that aligns with common DNS cache poisoning techniques described in various cybersecurity frameworks. The vulnerability directly corresponds to CWE-330, which addresses insufficient entropy in random number generation, and represents a clear violation of the principles outlined in the NIST SP 800-90A standard for random number generation.
The operational impact of this vulnerability extends beyond simple cache poisoning scenarios as it enables attackers to manipulate DNS resolution results for targeted domains. When adversaries can predict or guess the source port used by totd 1.5.3, they gain the capability to inject false DNS records into the resolver's cache, potentially redirecting users to malicious sites or disrupting legitimate network services. This attack vector operates under the ATT&CK framework's DNS tunneling and cache poisoning techniques, specifically mapping to T1071.004 for application layer protocol usage and T1496 for resource hijacking. The vulnerability affects organizations relying on totd as their DNS resolver, particularly those in environments where DNS security is critical such as enterprise networks, cloud deployments, or organizations handling sensitive data.
Mitigation strategies for this vulnerability require immediate implementation of source port randomization mechanisms within the totd resolver configuration. Administrators should ensure that the software generates randomized source ports for each upstream query, eliminating the predictable pattern that adversaries can exploit. The fix involves modifying the resolver's network communication stack to implement proper entropy generation for source port selection, which aligns with industry best practices for secure DNS implementations. Organizations should also consider implementing additional DNS security measures such as DNSSEC validation, recursive query filtering, and network monitoring to detect anomalous DNS traffic patterns. Regular security audits and vulnerability assessments should be conducted to ensure that similar entropy-related issues do not exist in other network services or applications within the infrastructure. The resolution of this vulnerability requires careful attention to the underlying network stack implementation and adherence to established security standards for protocol design and secure communication practices.