CVE-2017-12865 in ConnMan
Summary
by MITRE
Stack-based buffer overflow in "dnsproxy.c" in connman 1.34 and earlier allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted response query string passed to the "name" variable.
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Analysis
by VulDB Data Team • 01/10/2021
The vulnerability identified as CVE-2017-12865 represents a critical stack-based buffer overflow flaw within the connman network management daemon version 1.34 and earlier. This issue specifically affects the dnsproxy.c component which handles DNS proxy functionality, making it a significant concern for network infrastructure systems that rely on connman for network configuration and management. The vulnerability stems from inadequate input validation when processing DNS response queries, particularly in how the daemon handles the "name" variable within the DNS response parsing logic.
The technical implementation of this vulnerability occurs through a stack-based buffer overflow condition that arises when connman processes malformed DNS responses containing crafted query strings. When the daemon receives a specially crafted DNS response, it fails to properly validate the length of the name field in the DNS packet, allowing an attacker to overflow the allocated stack buffer. This type of vulnerability falls under the CWE-121 stack-based buffer overflow category, which is classified as a fundamental memory safety issue that can lead to arbitrary code execution or system crashes. The flaw is particularly dangerous because it operates within a network daemon that typically runs with elevated privileges, potentially providing attackers with a path to system compromise.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can enable remote code execution on affected systems. Attackers can leverage this vulnerability to crash the connman daemon, causing network connectivity disruptions, or more severely, execute arbitrary code with the privileges of the running daemon process. This presents a significant risk for embedded systems, IoT devices, and network appliances that utilize connman for network management, as these systems often have limited security controls and may be deployed in environments where persistent access is valuable. The vulnerability demonstrates how seemingly benign network protocol handling can become a critical attack surface when proper input validation is omitted.
Mitigation strategies for CVE-2017-12865 should focus on immediate patching of affected connman versions, with updates to version 1.35 or later that address the buffer overflow condition. Organizations should also implement network segmentation and monitoring to detect anomalous DNS traffic patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for command and control through DNS tunneling, as attackers could potentially use the compromised system to establish persistent communication channels. Additionally, implementing proper input validation and bounds checking in DNS response handling, along with regular security audits of network management components, would significantly reduce the risk exposure. System administrators should also consider deploying intrusion detection systems that can identify malformed DNS responses and implement network access controls to limit exposure of vulnerable systems to untrusted networks.