CVE-2016-10369 in lxterminal
Summary
by MITRE
unixsocket.c in lxterminal through 0.3.0 insecurely uses /tmp for a socket file, allowing a local user to cause a denial of service (preventing terminal launch), or possibly have other impact (bypassing terminal access control).
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/06/2022
The vulnerability identified as CVE-2016-10369 affects the lxterminal terminal emulator version 0.3.0 and earlier, specifically within the unixsocket.c component that handles socket file creation. This flaw represents a significant security weakness in the application's privilege escalation and access control mechanisms. The vulnerability stems from the application's insecure handling of temporary file creation, where it places socket files in the world-writable /tmp directory without proper security considerations.
The technical implementation of this vulnerability involves the application creating Unix domain socket files in the /tmp directory during terminal initialization. This directory is accessible to all users on the system and is typically not secured with appropriate permissions. When a local user can create files in /tmp, they can potentially create a malicious socket file with the same name as the legitimate one used by lxterminal. This allows the attacker to either prevent the legitimate terminal from launching by occupying the socket file or to potentially intercept and manipulate communications between the terminal and its associated processes.
From an operational perspective, this vulnerability enables a local attacker to achieve multiple malicious objectives within the system. The primary impact is denial of service, where the legitimate terminal application cannot launch due to socket file conflicts, effectively preventing authorized users from accessing their terminal sessions. Additionally, the vulnerability could potentially allow privilege escalation or access control bypass, as the attacker might be able to manipulate terminal operations or gain unauthorized access to terminal functionalities. This represents a direct violation of the principle of least privilege and can be categorized under CWE-377 as insecure temporary file handling.
The security implications extend beyond simple denial of service to encompass potential privilege escalation and access control bypass scenarios. Attackers can exploit this weakness by creating symbolic links or hard links in the /tmp directory that point to sensitive files or directories, or by simply occupying the socket file location. This type of vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and T1548.001 which addresses 'Abuse Elevation Control Mechanism'. The vulnerability essentially allows local users to manipulate the terminal's socket communication channel and potentially compromise the integrity of terminal operations.
Mitigation strategies for this vulnerability should focus on proper socket file handling and secure temporary file creation practices. The application should create socket files in secure directories with appropriate permissions rather than using world-writable locations like /tmp. Implementing proper file permissions, using secure temporary directory creation with appropriate ownership and access controls, and employing proper socket file naming conventions that prevent conflicts are essential measures. Additionally, the application should validate socket file existence and permissions before attempting to use them, and implement proper error handling to prevent attackers from exploiting the socket creation process. System administrators should also consider implementing file system monitoring to detect suspicious activities in temporary directories and ensure that applications do not create files in insecure locations without proper security controls. The vulnerability highlights the critical importance of secure coding practices and proper resource management in terminal emulators and similar system applications.