CVE-2017-8331 in Almond
Summary
by MITRE
An issue was discovered on Securifi Almond, Almond+, and Almond 2015 devices with firmware AL-R096. The device provides a user with the capability of adding new port forwarding rules to the device. It seems that the POST parameters passed in this request to set up routes on the device can be set in such a way that would result in passing commands to a "system" API in the function and thus result in command injection on the device. If the firmware version AL-R096 is dissected using binwalk tool, we obtain a cpio-root archive which contains the filesystem set up on the device that contains all the binaries. The binary "goahead" is the one that has the vulnerable function that recieves the values sent by the POST request. If we open this binary in IDA-pro we will notice that this follows a MIPS little endian format. The function sub_43C280in IDA pro is identified to be receiving the values sent in the POST request and the value set in POST parameter "ip_address" is extracted at address 0x0043C2F0. The POST parameter "ipaddress" is concatenated at address 0x0043C958 and this is passed to a "system" function at address 0x00437284. This allows an attacker to provide the payload of his/her choice and finally take control of the device.
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Analysis
by VulDB Data Team • 10/06/2023
The vulnerability identified in CVE-2017-8331 represents a critical command injection flaw affecting Securifi Almond, Almond+, and Almond 2015 devices running firmware version AL-R096. This issue stems from inadequate input validation within the device's web interface management system, specifically within the port forwarding rule configuration functionality. The vulnerability manifests when attackers can manipulate POST parameters to execute arbitrary system commands through a vulnerable function in the goahead web server binary. The security implications extend beyond simple command execution as this flaw enables full device compromise and unauthorized access to the embedded system. The affected devices operate on a MIPS little endian architecture, with the vulnerable code residing in the goahead binary that handles web requests from the device's management interface. The attack vector leverages the POST parameter processing where the ip_address field is extracted at memory address 0x0043C2F0 and subsequently concatenated at address 0x0043C958 before being passed to the system() function at address 0x00437284. This architectural design flaw allows attackers to inject malicious commands that bypass normal security controls and execute with the privileges of the web server process. The vulnerability directly maps to CWE-77 which describes improper neutralization of special elements used in a command, and aligns with ATT&CK technique T1059.001 for command and script injection. The device's firmware structure, when analyzed using tools like binwalk, reveals a cpio-root archive containing the complete filesystem including the vulnerable goahead binary. This binary serves as the primary attack surface where the command injection vulnerability exists, making it a prime target for exploitation. The exploitation process requires minimal privileges since the web interface already provides access to the device's management functions, and the vulnerability exists within the core functionality of the device's network configuration system. The impact extends to potential network compromise as attackers can establish persistent access to the device and potentially use it as a foothold for further network exploration. The vulnerability's exploitation does not require specialized tools beyond standard web application penetration testing methodologies, making it particularly dangerous in environments where IoT devices are deployed without proper network segmentation or security monitoring. Organizations should consider implementing network-based intrusion detection systems to monitor for exploitation attempts and ensure firmware updates are deployed promptly to address this vulnerability. The presence of this vulnerability in consumer IoT devices highlights the critical need for robust input validation and secure coding practices in embedded systems, particularly those handling network configuration and management functions.