CVE-2018-19640 in Supportutils
Summary
by MITRE
If the attacker manages to create files in the directory used to collect log files in supportutils before version 3.1-5.7.1 (e.g. with CVE-2018-19638) he can kill arbitrary processes on the local machine.
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Analysis
by VulDB Data Team • 07/26/2023
The vulnerability identified as CVE-2018-19640 represents a critical privilege escalation flaw within the supportutils package, specifically affecting versions prior to 3.1-5.7.1. This issue stems from inadequate directory permissions and file handling mechanisms that allow malicious actors to manipulate log file collection directories. The vulnerability is particularly dangerous because it enables attackers to execute arbitrary process termination commands on the local system, potentially disrupting critical services and compromising system integrity. The flaw exists in the way supportutils manages its temporary storage for log files, creating an attack surface where unauthorized file creation can lead to system-wide consequences.
The technical implementation of this vulnerability involves the manipulation of directory structures used for log collection, where the attacker can create malicious files that influence how supportutils processes log data. When supportutils attempts to handle these manipulated files, it executes commands that result in arbitrary process termination. This behavior aligns with CWE-276, which addresses improper permissions and access control mechanisms, and represents a classic case of privilege escalation through insecure file handling. The vulnerability demonstrates poor input validation and insufficient access control checks within the software's file processing pipeline, allowing local privilege escalation through manipulation of the logging infrastructure.
The operational impact of CVE-2018-19640 extends beyond simple process termination, as it can be leveraged to disrupt system services and potentially escalate privileges further. An attacker who has already established a foothold through related vulnerabilities such as CVE-2018-19638 can use this weakness to kill critical system processes, including security services or monitoring tools. This capability significantly undermines system stability and can be used as part of a broader attack chain to maintain persistence or escalate privileges. The vulnerability operates at the system level and can affect any process running with elevated privileges during log file processing, making it particularly dangerous in enterprise environments where supportutils is commonly deployed.
Mitigation strategies for CVE-2018-19640 should focus on immediate version updates to supportutils 3.1-5.7.1 or later, which contain the necessary patches to address the directory permission and file handling issues. System administrators should implement strict access controls on log file directories, ensuring that only authorized processes can write to these locations. The principle of least privilege should be enforced by configuring supportutils to run with minimal required permissions and by implementing proper directory ownership and permission settings. Additionally, monitoring for unauthorized file creation in log directories should be implemented as part of security operations procedures. Organizations should also consider implementing the ATT&CK framework's mitigation strategies for privilege escalation techniques, particularly those related to process injection and execution through legitimate system tools, as this vulnerability can be exploited as part of a broader attack pattern targeting system integrity and availability.