CVE-2020-25928 in NicheStack TCPIP
Summary
by MITRE • 08/19/2021
The DNS feature in InterNiche NicheStack TCP/IP 4.0.1 is affected by: Buffer Overflow. The impact is: execute arbitrary code (remote). The component is: DNS response processing functions: dns_upcall(), getoffset(), dnc_set_answer(). The attack vector is: a specific DNS response packet. The code does not check the "response data length" field of individual DNS answers, which may cause out-of-bounds read/write operations, leading to Information leak, Denial-or-Service, or Remote Code Execution, depending on the context.
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Analysis
by VulDB Data Team • 08/21/2021
The vulnerability identified as CVE-2020-25928 affects InterNiche NicheStack TCP/IP version 4.0.1, specifically within its DNS feature implementation. This represents a critical buffer overflow condition that exists in the DNS response processing functions, namely dns_upcall(), getoffset(), and dnc_set_answer(). The flaw manifests when the system processes specific DNS response packets without properly validating the response data length field associated with individual DNS answers. This omission creates a dangerous condition where memory operations can extend beyond allocated buffers, potentially resulting in arbitrary code execution at remote locations.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios. The attack vector requires a malicious DNS response packet to be processed by the vulnerable system, making it particularly dangerous in network environments where DNS traffic is not properly filtered or validated. When the DNS processing functions encounter malformed response data, they perform out-of-bounds read/write operations that can corrupt memory structures and potentially allow attackers to inject and execute malicious code remotely.
The operational impact of this vulnerability extends beyond simple denial-of-service conditions to encompass full system compromise capabilities. Depending on the memory layout and system context when the buffer overflow occurs, attackers can achieve information leakage through memory corruption, cause system crashes or hangs, or more critically, execute arbitrary code remotely. This remote code execution capability transforms the vulnerability from a mere network disruption into a severe security threat that could enable attackers to gain complete control over affected systems. The vulnerability affects systems that rely on InterNiche NicheStack TCP/IP for network communications, particularly embedded devices or applications that process DNS responses without proper input validation.
Mitigation strategies for CVE-2020-25928 should prioritize immediate patching of affected InterNiche NicheStack TCP/IP implementations to version 4.0.2 or later, which includes proper bounds checking for DNS response data lengths. Network administrators should implement DNS filtering mechanisms to prevent processing of suspicious DNS responses and consider deploying DNS security solutions that can detect and block malformed DNS traffic. Additional protective measures include implementing network segmentation to isolate systems running vulnerable versions, enabling intrusion detection systems to monitor for DNS-related anomalies, and establishing proper input validation procedures for all network protocol processing functions. Organizations should also consider implementing the principle of least privilege for DNS processing components and regularly audit their network infrastructure for vulnerable software implementations. The ATT&CK framework categorizes this vulnerability under T1071.004 for DNS tunneling and T1203 for Exploitation for Client Execution, highlighting the need for comprehensive network security monitoring and endpoint protection measures to detect and prevent exploitation attempts.