CVE-2025-32743 in ConnMan
Summary
by MITRE • 04/10/2025
In ConnMan through 1.44, the lookup string in ns_resolv in dnsproxy.c can be NULL or an empty string when the TC (Truncated) bit is set in a DNS response. This allows attackers to cause a denial of service (application crash) or possibly execute arbitrary code, because those lookup values lead to incorrect length calculations and incorrect memcpy operations.
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Analysis
by VulDB Data Team • 04/10/2025
The vulnerability identified as CVE-2025-32743 affects ConnMan version 1.44 and earlier, representing a critical security flaw within the network management daemon's DNS resolution functionality. This issue resides in the dnsproxy.c file where the ns_resolv function processes DNS responses. The vulnerability manifests when the TC (Truncated) bit is set in a DNS response packet, creating a condition where the lookup string can become NULL or an empty string during the resolution process. This fundamental flaw in input validation and error handling creates a dangerous pathway for malicious exploitation.
The technical implementation of this vulnerability stems from improper handling of DNS response truncation scenarios within the ConnMan daemon's DNS proxy functionality. When a DNS response contains the TC bit set, indicating that the response was truncated, the ns_resolv function fails to properly validate the lookup string parameter before proceeding with memory operations. This validation failure leads to catastrophic consequences including buffer overflows, memory corruption, and ultimately application crashes. The flaw specifically impacts the length calculation and memcpy operations that occur when processing these truncated DNS responses, creating opportunities for both denial of service attacks and potential code execution.
From an operational perspective, this vulnerability presents significant risks to systems relying on ConnMan for network management, particularly in environments where network services are critical and availability is paramount. An attacker could exploit this vulnerability by crafting malicious DNS responses with the TC bit set, causing the ConnMan daemon to crash and restart repeatedly, thereby creating a persistent denial of service condition. The potential for arbitrary code execution adds another layer of severity, as successful exploitation could allow attackers to gain control over the affected system. This vulnerability affects any system running ConnMan version 1.44 or earlier, making it particularly concerning given the widespread use of this network management tool in various embedded systems and Linux-based platforms.
The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read scenarios. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 for network denial of service and potentially T1059 for command and control execution. The attack surface is particularly concerning in IoT devices, embedded systems, and network appliances that utilize ConnMan for network configuration and management. Organizations should prioritize immediate patching of affected systems, as the vulnerability can be exploited remotely without authentication. Mitigation strategies include implementing proper input validation for DNS responses, deploying network monitoring to detect abnormal DNS traffic patterns, and applying network segmentation to limit exposure. Additionally, system administrators should consider implementing intrusion detection systems to monitor for potential exploitation attempts targeting this specific vulnerability pattern.