CVE-2018-13307 in A3002RU
Summary
by MITRE
System command injection in fromNtp in TOTOLINK A3002RU version 1.0.8 allows attackers to execute system commands via the "ntpServerIp2" POST parameter. Certain payloads cause the device to become permanently inoperable.
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Analysis
by VulDB Data Team • 04/15/2020
The vulnerability identified as CVE-2018-13307 represents a critical system command injection flaw within the TOTOLINK A3002RU router firmware version 1.0.8. This issue resides in the fromNtp function which processes network time protocol server parameters, specifically the "ntpServerIp2" POST parameter. The vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly escape or filter user-supplied data before incorporating it into system commands. This allows malicious actors to inject arbitrary commands that execute with the privileges of the affected device's system processes, effectively providing remote code execution capabilities.
The technical exploitation of this vulnerability follows a classic command injection pattern where attacker-controlled input is concatenated directly into system command strings without proper sanitization. When the device processes the "ntpServerIp2" parameter through the fromNtp function, it constructs system calls that include the user-supplied value without appropriate escaping or validation. This creates a pathway for attackers to execute arbitrary system commands, potentially gaining full control over the device's functionality. The vulnerability is particularly dangerous because it allows for persistent command execution that can be leveraged to modify device configuration, install malicious software, or establish backdoor access points.
The operational impact of this vulnerability extends beyond simple remote code execution to include potential device bricking scenarios. Certain malicious payloads designed to exploit this flaw can cause the device to become permanently inoperable, rendering the router unusable and requiring physical replacement or recovery procedures. This makes the vulnerability particularly attractive to attackers seeking to cause denial of service or to eliminate evidence of compromise. The affected TOTOLINK A3002RU model represents a common consumer-grade router that typically operates in home and small office environments, making it a valuable target for attackers seeking to establish persistent access points within networks. The vulnerability affects the device's network time synchronization functionality, which is a critical service that many network administrators rely upon for proper time management across networked systems.
This vulnerability maps directly to CWE-77 and CWE-88 within the Common Weakness Enumeration framework, specifically addressing command injection flaws where user-supplied data is improperly handled in system command construction. The ATT&CK framework categorizes this under T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation. The attack surface is particularly concerning as it requires no authentication to exploit, making it an attractive target for automated scanning and exploitation campaigns. Organizations should immediately assess their network exposure to this vulnerability, particularly in environments where TOTOLINK A3002RU devices are deployed. The lack of authentication requirements combined with the potential for permanent device damage makes this vulnerability particularly dangerous in both corporate and home network environments.
Mitigation strategies should include immediate firmware updates from TOTOLINK to address the command injection flaw, network segmentation to limit exposure, and implementation of intrusion detection systems to monitor for exploitation attempts. Network administrators should also consider disabling unnecessary services and implementing strict input validation controls. The vulnerability highlights the critical importance of proper input sanitization and the potential for seemingly benign configuration parameters to become attack vectors. Regular security assessments of network infrastructure, particularly legacy devices, are essential to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.