CVE-2017-2100 in AppGoat for Web Application
Summary
by MITRE
Hands-on Vulnerability Learning Tool "AppGoat" for Web Application V3.0.1 and earlier allows remote attackers to conduct DNS rebinding attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 09/21/2020
The vulnerability identified as CVE-2017-2100 resides within the Hands-on Vulnerability Learning Tool known as AppGoat version 3.0.1 and earlier, which serves as an educational platform for web application security training. This tool is designed to provide hands-on experience with various security vulnerabilities to help security professionals and students understand common web application flaws. However, the presence of a DNS rebinding vulnerability in this educational software creates a significant security risk that could potentially be exploited by malicious actors. The vulnerability specifically affects the tool's handling of DNS resolution and network communications, making it susceptible to attacks that could compromise its security posture and potentially be leveraged to exploit other systems.
DNS rebinding attacks exploit the way DNS resolution works by manipulating the timing and responses from DNS servers to trick applications into making connections to internal network resources that would normally be protected by network segmentation. The vulnerability in AppGoat allows remote attackers to conduct these attacks through unspecified vectors, indicating that the tool's network communication handling lacks proper validation and protection mechanisms. This type of attack typically involves an attacker controlling a DNS server that returns different IP addresses for the same domain name, enabling them to redirect traffic from external connections to internal network resources. The attack can be particularly dangerous when the vulnerable application has access to internal resources or when it processes user input without proper sanitization and validation.
The operational impact of this vulnerability extends beyond the immediate security risk to the AppGoat tool itself. Since this is an educational platform, the vulnerability could potentially be exploited to demonstrate how attackers might bypass network security controls in real-world scenarios, but it also creates a risk that attackers could use the tool itself as a stepping stone for more serious attacks. The vulnerability affects the tool's ability to properly isolate network communications and validate external inputs, which undermines its effectiveness as a secure learning environment. Organizations using this tool for security training may inadvertently expose their networks to attacks, particularly if the tool is deployed in environments with limited network segmentation or if it has access to sensitive internal systems. The potential for attackers to leverage this vulnerability to gain unauthorized access to internal resources makes it particularly concerning for organizations that rely on such educational tools.
Mitigation strategies for this vulnerability should focus on implementing proper DNS validation mechanisms and network communication controls within the AppGoat tool. Organizations should ensure that any version of the tool is updated to the latest release that addresses this vulnerability, as the developers likely implemented proper DNS resolution handling and input validation. Network segmentation should be implemented to isolate the educational tool from critical internal systems, and proper access controls should be enforced to limit the tool's network capabilities. The implementation of DNS rebinding protection measures such as proper DNS TTL handling, connection validation, and IP address verification should be enforced. Additionally, organizations should consider deploying the tool in a sandboxed environment with limited network access and ensure that any external communications are properly monitored and logged. This vulnerability aligns with CWE-1004 which addresses insecure default configurations, and could potentially be mapped to ATT&CK technique T1133 which covers external remote services, particularly in the context of how the tool might be used to demonstrate or exploit network access vectors.