CVE-2024-43387 in FL MGUARD 2102
Summary
by MITRE • 09/10/2024
A low privileged remote attacker can read and write files as root due to improper neutralization of special elements in the variable EMAIL_RELAY_PASSWORD in mGuard devices.
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Analysis
by VulDB Data Team • 09/11/2024
This vulnerability exists within mGuard devices where a low privileged remote attacker can escalate privileges to gain root access and perform unauthorized file operations. The flaw stems from inadequate sanitization of input variables, specifically the EMAIL_RELAY_PASSWORD variable which contains special elements that are not properly neutralized. This improper handling creates a path for attackers to manipulate system behavior through crafted input that bypasses normal access controls.
The technical implementation of this vulnerability leverages a classic command injection or configuration manipulation vector where the EMAIL_RELAY_PASSWORD variable is processed without sufficient validation or sanitization. When the system processes this variable, it fails to neutralize special characters that could be interpreted as command sequences or path traversal elements. This allows an attacker to inject malicious payloads that are executed with root privileges, effectively bypassing the standard user permission model.
From an operational perspective, this vulnerability represents a critical security weakness that undermines the fundamental principle of least privilege. The ability to read and write files as root provides attackers with complete system control, enabling data exfiltration, persistence mechanisms, and further network exploitation. The low privilege requirement for exploitation means that even minimal authentication credentials can be sufficient to initiate the attack chain, making this vulnerability particularly dangerous in environments where device access controls are not properly enforced.
The vulnerability aligns with CWE-77 and CWE-78 categories from the Common Weakness Enumeration, specifically addressing improper neutralization of special elements in command execution contexts. It also maps to ATT&CK techniques such as T1059.001 for command and scripting interpreter and T1566 for spearphishing with a malicious attachment, as attackers could exploit this weakness to establish persistent access. The attack surface is further expanded by the remote nature of the vulnerability, allowing exploitation from external networks without requiring physical access to the device.
Mitigation strategies should include immediate input validation and sanitization of all user-supplied data, particularly configuration variables like EMAIL_RELAY_PASSWORD. System administrators should implement proper access controls and privilege separation, ensuring that configuration variables are processed through secure parsing functions that neutralize special characters before system processing. Network segmentation and firewall rules should be implemented to limit remote access to administrative interfaces, while regular security updates and patch management procedures should be enforced to address similar vulnerabilities. Additionally, monitoring and logging should be enhanced to detect anomalous file access patterns that could indicate exploitation attempts, and regular security audits should be conducted to identify and remediate similar input validation weaknesses across the device firmware.