CVE-2022-30295 in uClibc
Summary
by MITRE • 05/06/2022
uClibc-ng through 1.0.40 and uClibc through 0.9.33.2 use predictable DNS transaction IDs that may lead to DNS cache poisoning. This is related to a reset of a value to 0x2.
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Analysis
by VulDB Data Team • 05/11/2022
The vulnerability identified as CVE-2022-30295 affects uClibc-ng versions through 1.0.40 and uClibc versions through 0.9.33.2, representing a significant security flaw in DNS resolution mechanisms within embedded systems and lightweight applications. This issue stems from the predictable nature of DNS transaction IDs, which are critical for maintaining the integrity of DNS communications and preventing cache poisoning attacks. The vulnerability specifically relates to a reset operation that initializes a value to 0x2, creating a predictable sequence that adversaries can exploit to manipulate DNS responses.
The technical implementation of this flaw resides in the DNS client library's handling of transaction identifiers, which are supposed to be random values that distinguish between different DNS queries and responses. When these identifiers become predictable due to improper initialization or reset operations, attackers can monitor DNS traffic and inject malicious responses that match the predictable transaction ID, thereby poisoning the DNS cache of affected systems. This vulnerability is classified under CWE-330 as the use of insufficiently random values, and it directly impacts the integrity of DNS resolution processes that are fundamental to network communication.
The operational impact of CVE-2022-30295 extends beyond simple cache poisoning to potentially enable more sophisticated attacks including man-in-the-middle operations, redirection to malicious sites, and disruption of network services. Systems utilizing affected uClibc versions are particularly vulnerable as they are commonly found in embedded devices, IoT appliances, and lightweight applications where DNS resolution is critical for proper operation. The vulnerability affects environments where DNS cache poisoning can be leveraged to compromise network integrity, making it a significant concern for organizations relying on embedded systems and constrained computing environments.
Mitigation strategies for this vulnerability require immediate updates to affected uClibc-ng and uClibc versions to patched releases that properly implement random transaction ID generation. System administrators should prioritize patching embedded devices and IoT systems that may be running vulnerable versions of these libraries, as these environments often lack the robust security measures found in traditional computing environments. Additional defensive measures include implementing DNSSEC validation where possible, monitoring for suspicious DNS traffic patterns, and ensuring that network segmentation limits the potential impact of successful cache poisoning attempts. The vulnerability demonstrates the critical importance of proper random number generation in security-sensitive contexts and aligns with ATT&CK technique T1071.004 for application layer protocol: dns, where adversaries exploit predictable identifiers to manipulate DNS responses. Organizations should also consider implementing network monitoring solutions that can detect anomalous DNS behavior patterns that may indicate cache poisoning attempts.