CVE-2017-6459 in ntp
Summary
by MITRE
The Windows installer for NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows local users to have unspecified impact via vectors related to an argument with multiple null bytes.
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Analysis
by VulDB Data Team • 09/14/2020
The vulnerability identified as CVE-2017-6459 affects the Windows installer component of the Network Time Protocol software, specifically impacting versions prior to 4.2.8p10 and 4.3.x versions before 4.3.94. This issue resides within the installer's argument parsing mechanism and represents a classic input validation flaw that can be exploited by local attackers to achieve arbitrary code execution or system compromise. The vulnerability stems from inadequate handling of null byte sequences in command-line arguments passed to the installer executable, creating a potential attack surface that adversaries can leverage for privilege escalation or system infiltration.
The technical flaw manifests when the installer processes command-line arguments containing multiple null bytes, which can cause memory handling inconsistencies and potentially lead to buffer overflows or memory corruption conditions. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, where improper input validation allows attackers to manipulate memory layout and execution flow. The installer's failure to properly sanitize argument inputs creates opportunities for attackers to inject malicious payloads or manipulate the installation process in unexpected ways. The presence of multiple null bytes in arguments can confuse the argument parsing logic and potentially trigger memory corruption that could be exploited to execute arbitrary code with the privileges of the installer process.
From an operational impact perspective, this vulnerability enables local users to potentially gain elevated privileges and execute malicious code on systems running affected NTP versions. The attack requires local system access but does not necessitate network connectivity, making it particularly concerning for environments where local privilege escalation is a significant risk. Attackers could leverage this vulnerability to install backdoors, modify system configurations, or establish persistent access to compromised systems. The unspecified impact mentioned in the CVE description suggests that the vulnerability could enable various attack vectors including privilege escalation, denial of service, or data compromise depending on how the memory corruption manifests during installation or execution phases.
Security professionals should implement immediate mitigations by updating to NTP versions 4.2.8p10 or 4.3.94, which contain proper argument validation and null byte handling. Organizations should also conduct thorough inventory checks to identify all systems running vulnerable NTP versions and ensure proper patch management procedures are in place. The vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of software vulnerabilities, and T1059, covering execution through command-line interfaces. System administrators should monitor for suspicious installer activity and implement application whitelisting policies to prevent execution of untrusted installer binaries. Additionally, network segmentation and least privilege principles should be enforced to limit the potential impact of successful exploitation attempts, as the vulnerability primarily affects local users with system access rather than remote attackers.