NatShell Local File Inclusion Scanner

NatShell is used by organizations needing efficient billing management systems. It is commonly found in environments where billing processes need to be automated and managed securely. Small to medium-sized enterprises often deploy NatShell for its robust functionalities. The software is developed and maintained by entities focusing on network solutions. Its purpose is to streamline billing operations, ensuring accuracy and reliability. NatShell is recognized for its user-friendly interface and comprehensive billing capabilities.

The Local File Inclusion (LFI) vulnerability allows attackers to include files on a server using "include" functionality. It is often exploited to access sensitive files on the server, leading to unauthorized data exposure. The vulnerability can occur when the input for file selection is insufficiently validated, permitting directory traversal sequences. Attackers can utilize it to execute arbitrary code indirectly, breaching the system's security. LFI can be a gateway to more severe attacks on systems, including Remote Code Execution (RCE). This vulnerability poses significant risks, demanding prompt identification and mitigation.

LFI in NatShell is identified through the 'download.php' endpoint, with the 'file' parameter being susceptible. The vulnerability is triggered when file paths are manipulated to traverse directories, bypassing standard access controls. A typical exploit attempts to read '/etc/passwd', which contains critical user information. Successful exploitation returns a status code of 200, confirming access to the file. Regex matching confirms the inclusion by identifying specific text sequences. This exploit vector highlights the need for stringent input validation.

If exploited, the Local File Inclusion vulnerability can cause unauthorized data leaks. Sensitive information such as system configurations and user credentials might be compromised. This can lead to data breaches, impacting the organization's reputation and legal standing. Furthermore, the vulnerability might serve as a starting point for further exploitations, such as privilege escalation. Ultimately, it could lead to significant financial and operational disruptions. Proactive measures are essential to prevent exploitation and protect organizational assets.

REFERENCES

• https://mp.weixin.qq.com/s/g4YNI6UBqIQcKL0TRkKWlw