CVE-2018-10695 in AWK-3121
Summary
by MITRE
An issue was discovered on Moxa AWK-3121 1.14 devices. It provides alert functionality so that an administrator can send emails to his/her account when there are changes to the device's network. However, the same functionality allows an attacker to execute commands on the device. The POST parameters "to1,to2,to3,to4" are all susceptible to buffer overflow. By crafting a packet that contains a string of 678 characters, it is possible for an attacker to execute the attack.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 09/28/2023
The vulnerability identified in Moxa AWK-3121 version 1.14 represents a critical buffer overflow flaw within the device's email alert functionality that exposes the system to remote command execution. This issue affects the network monitoring appliance's configuration interface where administrators can set up email notifications for network changes. The device's web-based management interface processes POST parameters named "to1,to2,to3,to4" which are used to define recipient email addresses for alert notifications. These parameters lack proper input validation and bounds checking, creating an exploitable condition that allows attackers to inject malicious payloads through crafted email address specifications.
The technical implementation of this vulnerability stems from inadequate string handling within the device's firmware processing logic. When the system receives POST requests containing email addresses in the designated parameters, it fails to properly validate the length of input data before storing it in fixed-size buffers. The buffer overflow occurs specifically when an attacker submits a string exceeding 678 characters in any of the four to parameters, which triggers memory corruption that can be leveraged to overwrite critical program execution flow. This type of vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified as a common weakness in software design where insufficient bounds checking allows attackers to overwrite adjacent memory locations.
The operational impact of this vulnerability is severe as it enables remote code execution without authentication requirements, allowing attackers to gain full administrative control over the device. Once exploited, the attacker can manipulate network configurations, disable security features, redirect traffic, or establish persistent access points for further network infiltration. The device's role as a network monitoring appliance makes it particularly valuable to attackers who can use it as a foothold for broader network compromise. This vulnerability also aligns with ATT&CK technique T1059 Command and Scripting Interpreter, where adversaries leverage system command execution capabilities to establish persistence and escalate privileges. The lack of authentication requirements for exploitation makes this vulnerability particularly dangerous as it can be exploited from any network location without prior access credentials.
Mitigation strategies for this vulnerability should include immediate firmware updates from Moxa to address the buffer overflow conditions in the email alert functionality. Network administrators should implement strict input validation at network boundaries to filter out suspicious POST requests containing oversized parameters. The device configuration should be reviewed to disable unnecessary email alert features when not actively required for monitoring purposes. Additionally, network segmentation should be implemented to limit access to the device to authorized administrative networks only. Security monitoring should include detection of unusual POST request patterns targeting the affected parameters, and network administrators should consider implementing intrusion detection systems that can identify potential exploitation attempts through signature-based detection of the specific 678-character payload patterns. The vulnerability demonstrates the importance of input validation and bounds checking in embedded systems, particularly those with web interfaces that process user-provided data without proper sanitization.