CVE-2018-19246 in PHP-Proxy
Summary
by MITRE
PHP-Proxy 5.1.0 allows remote attackers to read local files if the default "pre-installed version" (intended for users who lack shell access to their web server) is used. This occurs because the aeb067ca0aa9a3193dce3a7264c90187 app_key value from the default config.php is in place, and this value can be easily used to calculate the authorization data needed for local file inclusion.
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Analysis
by VulDB Data Team • 06/23/2024
The vulnerability CVE-2018-19246 represents a critical security flaw in PHP-Proxy version 5.1.0 that exposes systems to unauthorized local file inclusion attacks. This issue specifically affects installations that utilize the default pre-installed configuration, which is designed for users who cannot access shell commands on their web servers. The vulnerability stems from a hardcoded application key value within the default configuration file that remains unchanged in many deployments. This default app_key value of aeb067ca0aa9a3193dce3a7264c90187 creates a predictable authentication mechanism that attackers can exploit to gain unauthorized access to local system files through the proxy interface.
The technical exploitation of this vulnerability relies on the predictable nature of the default cryptographic key used for authorization within the PHP-Proxy application. When the default configuration is not modified by administrators, the hardcoded app_key value allows attackers to calculate the necessary authorization data required for local file inclusion operations. This weakness directly relates to CWE-310, which addresses cryptographic issues and the use of weak or predictable cryptographic keys. The flaw demonstrates poor security practices in software distribution where default configurations contain hardcoded credentials that should be randomly generated and securely stored during installation. Attackers can leverage this predictable key to bypass authentication mechanisms and access sensitive files on the server, potentially including configuration files, database credentials, or other system information that could lead to further compromise.
The operational impact of this vulnerability extends beyond simple file disclosure, as it provides attackers with a foothold for more sophisticated attacks within the compromised environment. Once an attacker successfully exploits this vulnerability, they can potentially access not only local files but also gain insights into the server configuration, application structure, and potentially sensitive data stored on the system. This vulnerability is particularly dangerous in shared hosting environments or when the PHP-Proxy is used as a gateway to internal systems, as it could enable attackers to escalate their privileges or move laterally within the network. The attack vector is straightforward and requires minimal technical expertise, making it a high-risk vulnerability that could be exploited by both skilled attackers and automated tools. The vulnerability aligns with ATT&CK technique T1566, which covers the use of malicious files and the exploitation of software vulnerabilities to gain initial access to systems.
Organizations affected by this vulnerability should immediately implement several mitigation strategies to protect their systems. The primary recommendation is to modify the default configuration files and replace the hardcoded app_key with a randomly generated, secure value that is unique to each installation. Administrators should also ensure that all default configurations are reviewed and customized during the initial setup process, following security best practices for credential management and key generation. Additionally, network segmentation and access controls should be implemented to limit the exposure of the PHP-Proxy application to unauthorized users. Regular security audits and vulnerability assessments should be conducted to identify and remediate similar issues in other software components. The vulnerability also highlights the importance of keeping software updated and following secure configuration guidelines, as many of these issues can be prevented through proper deployment practices and adherence to security frameworks such as the OWASP Top Ten or NIST cybersecurity guidelines.