CVE-2023-40706 in SNAP PAC S1
Summary
by MITRE • 08/24/2023
There is no limit on the number of login attempts in the web server for the SNAP PAC S1 Firmware version R10.3b. This could allow for a brute-force attack on the built-in web server login.
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Analysis
by VulDB Data Team • 09/20/2023
The vulnerability identified as CVE-2023-40706 represents a critical authentication weakness in the SNAP PAC S1 firmware version R10.3b which operates a built-in web server for device management and configuration. This flaw stems from the absence of any rate-limiting or account lockout mechanisms within the web server's authentication process, creating an exploitable condition that fundamentally undermines the security posture of the affected industrial control system. The vulnerability is classified under CWE-307 which specifically addresses inadequate account lockout mechanisms, making it a direct descendant of well-established authentication security weaknesses that have plagued numerous industrial and embedded systems. The SNAP PAC S1 series represents a family of programmable automation controllers commonly deployed in industrial environments where unauthorized access could result in significant operational disruption or safety hazards.
The technical implementation of this vulnerability manifests through the web server's login interface which accepts unlimited authentication attempts without any form of throttling or account protection measures. Attackers can systematically iterate through password combinations using automated tools or scripts to perform brute-force attacks against the web server login credentials. The absence of any mechanism to detect or prevent repeated failed authentication attempts means that malicious actors can exhaustively test numerous password combinations until they successfully gain access to the system. This weakness is particularly concerning in industrial settings where the web server interface may provide administrative access to critical control system parameters, configuration settings, and operational data. The vulnerability affects the authentication mechanism at its core, eliminating any form of protection that would normally be expected in secure web applications and industrial control systems.
The operational impact of this vulnerability extends beyond simple unauthorized access as it creates a pathway for attackers to potentially compromise the entire industrial control environment. Once authenticated, an attacker could modify system configurations, access sensitive operational data, or even manipulate control processes that could affect production operations, safety systems, or environmental controls. The lack of account lockout functionality means that attackers can continue their attempts indefinitely without triggering any protective measures, making brute-force attacks particularly effective against systems with weak or default passwords. This vulnerability aligns with ATT&CK technique T1110 which covers credential access through brute force methods, and specifically represents a failure in the authentication process that enables adversaries to escalate their privileges within the industrial control system environment. The risk is amplified in environments where the web server interface provides access to critical infrastructure components that are not adequately protected by additional network security controls.
Mitigation strategies for this vulnerability should focus on implementing rate-limiting mechanisms and account lockout policies within the web server configuration. Organizations should immediately disable or restrict access to the built-in web server interface when possible, or implement network-level access controls to limit who can reach the web server. The most effective immediate solution involves applying firmware updates from the vendor that address the authentication weakness, as the vulnerability is specifically tied to the R10.3b firmware version. Network segmentation and firewall rules should be implemented to restrict access to the web server ports to only trusted administrative workstations. Additionally, strong password policies should be enforced with complex credentials and regular rotation schedules, though these measures alone cannot fully compensate for the lack of authentication protection mechanisms. Organizations should also consider implementing multi-factor authentication where possible and establish monitoring procedures to detect unusual login patterns that might indicate brute-force attack attempts. The vulnerability demonstrates the critical importance of proper authentication design in industrial control systems and highlights the need for security considerations in embedded systems that are often overlooked in favor of operational functionality.