CVE-2017-16256 in Insteon
Summary
by MITRE • 01/12/2023
Multiple exploitable buffer overflow vulnerabilities exist in the PubNub message handler for the "cc" channel of Insteon Hub running firmware version 1012. Specially crafted commands sent through the PubNub service can cause a stack-based buffer overflow overwriting arbitrary data. An attacker should send an authenticated HTTP request to trigger this vulnerability. In cmd sn_sx, at 0x9d014ebc, the value for the `cmd2` key is copied using `strcpy` to the buffer at `$sp+0x2d0`.This buffer is 100 bytes large, sending anything longer will cause a buffer overflow.
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Analysis
by VulDB Data Team • 02/04/2023
The vulnerability described in CVE-2017-16256 represents a critical stack-based buffer overflow in the Insteon Hub's PubNub message handling system, specifically within the "cc" channel functionality. This flaw exists in firmware version 1012 and demonstrates a classic security weakness where unbounded string copying operations create opportunities for arbitrary code execution. The vulnerability manifests through the insecure use of the strcpy function, which lacks bounds checking and allows attackers to overwrite adjacent memory locations on the stack. The affected component operates within the cmd sn_sx function at memory address 0x9d014ebc, where the cmd2 parameter from incoming PubNub messages is directly copied into a 100-byte buffer located at stack offset $sp+0x2d0 without proper validation of input length.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides attackers with the ability to manipulate program execution flow through stack-based buffer overflow techniques. When an attacker sends an authenticated HTTP request containing maliciously crafted data through the PubNub service, they can overwrite critical stack memory regions including return addresses, saved registers, and other program state information. This allows for potential privilege escalation and remote code execution within the context of the Insteon Hub's operating environment. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions where insufficient bounds checking permits memory corruption. The attack vector requires authentication through the HTTP interface, making it accessible to users with valid credentials but still representing a significant security risk for home automation systems.
From an adversarial perspective, this vulnerability maps directly to several ATT&CK techniques including T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation. The attacker can leverage the buffer overflow to inject and execute malicious code within the device's memory space, potentially gaining persistent access to the home automation network. The use of PubNub as the communication channel adds complexity to detection since legitimate messaging traffic may mask malicious payloads, making this vulnerability particularly dangerous in environments where the device operates continuously and maintains network connectivity. The specific implementation flaw involving strcpy usage rather than safer alternatives like strlcpy or strncpy represents a common security anti-pattern that has been documented in numerous security advisories and vulnerability assessments. Mitigation strategies should focus on input validation, proper memory management practices, and implementing defensive programming techniques such as stack canaries and address space layout randomization to prevent successful exploitation attempts.