CVE-2018-18876 in MicroServer
Summary
by MITRE
In firmware version MS_2.6.9900 of Columbia Weather MicroServer, a readouts_rd.php directory traversal issue makes it possible to read any file present on the underlying operating system.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/06/2023
The vulnerability identified as CVE-2018-18876 affects the Columbia Weather MicroServer firmware version MS_2.6.9900, presenting a critical directory traversal flaw in the readouts_rd.php component. This issue stems from inadequate input validation and sanitization within the web application interface, allowing remote attackers to manipulate file access requests through crafted URI parameters. The vulnerability enables unauthorized access to sensitive system files that should remain protected within the operating system's file hierarchy, potentially exposing confidential data, configuration files, and system resources.
This directory traversal vulnerability maps directly to CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw operates by allowing attackers to manipulate file path parameters through special characters such as dot-dot-slash sequences or encoded path separators, effectively bypassing intended access controls. The attack vector is particularly dangerous because it requires no authentication and can be executed remotely, making it highly exploitable in networked environments where the weather microserver serves as a data collection and dissemination platform.
The operational impact of this vulnerability extends beyond simple file access, as it provides attackers with the potential to extract sensitive information from the underlying operating system. Attackers could access system configuration files, user credentials, application logs, and other confidential data that might reveal network topology, system architecture, or authentication mechanisms. Given that weather microservers typically process and store environmental data that may include sensitive location information or proprietary meteorological calculations, the exposure of such data could result in significant operational and security implications. The vulnerability also opens pathways for further exploitation, including potential privilege escalation or lateral movement within networked environments where the device operates.
Security professionals should implement immediate mitigations including input validation and sanitization of all user-supplied data, particularly URI parameters and file path inputs. The firmware should be updated to the latest available version from the vendor, as this vulnerability is likely addressed in subsequent releases. Network segmentation and access controls should be enforced to limit exposure of the weather microserver to untrusted networks. Additionally, implementing web application firewalls and monitoring for suspicious file access patterns can help detect and prevent exploitation attempts. Organizations should also conduct thorough security assessments of all networked devices to identify similar vulnerabilities in other systems, as this type of directory traversal flaw commonly exists in legacy embedded systems and older firmware versions. The vulnerability demonstrates the critical importance of secure coding practices and regular firmware updates in maintaining operational security for IoT and embedded systems.