CVE-2025-1673 in Zephyr
Summary
by MITRE • 02/25/2025
A malicious or malformed DNS packet without a payload can cause an out-of-bounds read, resulting in a crash (denial of service) or an incorrect computation.
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Analysis
by VulDB Data Team • 02/28/2025
This vulnerability represents a critical buffer over-read condition in DNS processing systems that can be exploited through malformed DNS packets lacking payload data. The flaw manifests when network infrastructure components receive DNS queries or responses that contain no actual data payload, yet the parsing logic fails to properly validate the packet structure before attempting to access memory regions. This specific vulnerability falls under the category of out-of-bounds memory access issues, which are classified as CWE-125 in the Common Weakness Enumeration catalog and represent a fundamental class of memory safety flaws that can lead to system instability. The technical implementation involves the DNS resolver or server attempting to process a packet header that indicates a valid DNS message structure while containing zero-length data sections, causing the application to read memory beyond allocated boundaries.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as the out-of-bounds read can potentially lead to information disclosure or incorrect computation results that may affect downstream applications. When exploited, the vulnerability can cause network services to crash and restart, creating availability issues that can be particularly damaging in mission-critical infrastructure environments. The attack vector requires minimal sophistication as it only necessitates sending malformed DNS packets to the target system, making it particularly dangerous in environments where DNS traffic is not properly filtered or monitored. This type of vulnerability aligns with ATT&CK technique T1071.004 for application layer protocol manipulation and can be leveraged as part of broader network reconnaissance or disruption campaigns.
Mitigation strategies should focus on implementing robust input validation mechanisms that properly check packet structures before processing, including bounds checking on all memory access operations and implementing proper error handling for malformed DNS traffic. Network administrators should deploy DNS filtering solutions that can detect and block malformed packets at the perimeter, while also ensuring that all DNS infrastructure components are regularly updated with security patches. The vulnerability demonstrates the importance of defensive programming practices and adherence to secure coding standards that prevent memory safety issues, particularly in network protocol implementations where malformed input is expected. Organizations should also consider implementing intrusion detection systems that can identify patterns of DNS traffic that may indicate exploitation attempts, as well as establishing incident response procedures specifically for DNS-related security events.