CVE-2019-18922 in AT-GS950-8
Summary
by MITRE
A Directory Traversal in the Web interface of the Allied Telesis AT-GS950/8 until Firmware AT-S107 V.1.1.3 [1.00.047] allows unauthenticated attackers to read arbitrary system files via a GET request. NOTE: This is an End-of-Life product.
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Analysis
by VulDB Data Team • 06/23/2024
The vulnerability identified as CVE-2019-18922 represents a critical directory traversal flaw within the web interface of Allied Telesis AT-GS950/8 network switches. This issue affects firmware versions up to AT-S107 V.1.1.3 with build 1.00.047, exposing devices to unauthorized access through unauthenticated GET requests that can retrieve arbitrary system files. The affected device operates under the Common Weakness Enumeration framework as CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as path traversal or directory traversal attacks. Such vulnerabilities are particularly dangerous in network infrastructure devices as they can provide attackers with access to sensitive system information that may include configuration files, user credentials, and other critical operational data.
The technical exploitation of this vulnerability occurs through manipulation of file path parameters within HTTP GET requests sent to the web interface of the affected network switch. Attackers can construct malicious URLs that leverage directory traversal sequences such as ../ or ..\ to navigate outside the intended web root directory and access system files that should remain protected. This flaw allows unauthorized individuals to bypass authentication mechanisms entirely, as the vulnerability does not require valid credentials to exploit. The attack vector specifically targets the web server component of the switch's firmware, where input validation is insufficient to prevent malicious path manipulation attempts. The vulnerability's impact is amplified by the fact that it affects an end-of-life product, meaning vendors have ceased providing security updates or patches, leaving devices permanently exposed to this threat.
From an operational security perspective, this vulnerability poses significant risks to network infrastructure integrity and data confidentiality. Network administrators who have deployed these switches may unknowingly leave their systems vulnerable to attackers who can extract sensitive information including device configurations, potentially exposing network topology details, administrative credentials, and other operational parameters. The lack of authentication requirements makes this particularly dangerous as it allows any remote attacker to exploit the vulnerability without requiring prior access to the network or valid credentials. This type of attack can lead to complete network compromise, as attackers can use the extracted information to plan more sophisticated attacks or escalate privileges within the network environment. The vulnerability also represents a failure in the principle of least privilege, where the web interface should have restricted access to only necessary files and functions while maintaining proper input validation.
Organizations affected by this vulnerability should consider immediate mitigations including network segmentation to isolate the vulnerable switches from critical network segments, implementing network access controls to restrict web interface access, and monitoring for suspicious network traffic patterns that may indicate exploitation attempts. The recommended approach for addressing this vulnerability involves upgrading to firmware versions that have patched this directory traversal flaw, although the end-of-life status of the product means that such updates may no longer be available from the vendor. Security professionals should also consider implementing intrusion detection systems to monitor for exploitation attempts and conducting comprehensive network audits to identify all instances of this vulnerable hardware. Additionally, organizations should evaluate their overall network security posture and consider replacing end-of-life network infrastructure with supported devices that receive regular security updates and patches, as outlined in the ATT&CK framework's network infrastructure component where such vulnerabilities are categorized under privilege escalation and credential access techniques. The vulnerability demonstrates the critical importance of maintaining up-to-date network equipment and implementing proper security controls for legacy systems that no longer receive vendor support.