CVE-2023-29181 in FortiOS
Summary
by MITRE • 02/22/2024
A use of externally-controlled format string in Fortinet FortiOS 7.2.0 through 7.2.4, 7.0.0 through 7.0.11, 6.4.0 through 6.4.12, 6.2.0 through 6.2.14, 6.0.0 through 6.0.16, FortiProxy 7.2.0 through 7.2.4, 7.0.0 through 7.0.10, 2.0.0 through 2.0.12, 1.2.0 through 1.2.13, 1.1.0 through 1.1.6, 1.0.0 through 1.0.7, FortiPAM 1.0.0 through 1.0.3 allows attacker to execute unauthorized code or commands via specially crafted command.
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Analysis
by VulDB Data Team • 12/11/2024
This vulnerability represents a critical format string vulnerability affecting multiple Fortinet products including FortiOS, FortiProxy, and FortiPAM across several version ranges. The flaw exists in the handling of externally controlled input within format string operations, creating a path for remote code execution through specially crafted commands. This issue stems from improper validation and sanitization of user-supplied input that gets processed through format string functions without adequate protection against malicious payload injection.
The technical implementation of this vulnerability leverages the fundamental weakness in how format string parameters are processed within the affected software components. When an attacker supplies malicious input that contains format specifiers such as %s, %d, or %x, the application fails to properly validate or escape these elements before processing them through functions like printf or sprintf. This allows attackers to manipulate the execution flow and potentially execute arbitrary code on the affected system. The vulnerability is particularly dangerous because it affects multiple product lines and version ranges, amplifying its potential impact across various network security infrastructures.
From an operational perspective, this vulnerability creates significant risk for organizations relying on Fortinet security appliances, as it enables remote attackers to gain unauthorized access and execute commands without authentication. The attack surface is broad given that the vulnerability affects FortiOS versions 7.2.0 through 7.2.4, 7.0.0 through 7.0.11, 6.4.0 through 6.4.12, 6.2.0 through 6.2.14, and 6.0.0 through 6.0.16, along with multiple FortiProxy and FortiPAM versions. This means that organizations with legacy deployments or those using older versions of these security products face substantial exposure to compromise. The vulnerability can be exploited from external networks, making it particularly dangerous for perimeter security devices.
The security implications extend beyond simple command execution to potentially allow full system compromise and lateral movement within network environments. Attackers could leverage this vulnerability to establish persistent access, escalate privileges, or use the compromised device as a pivot point for attacking other systems. This aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation. Organizations should consider implementing network segmentation and monitoring for unusual command execution patterns as part of their defensive strategy.
Mitigation strategies should include immediate patching of all affected versions to address the root cause of the vulnerability. Organizations should also implement network-based protections such as intrusion detection systems that can detect format string attack patterns and firewall rules that restrict access to vulnerable services. Additionally, input validation controls should be strengthened to prevent format string specifiers from being processed through vulnerable functions. The vulnerability classification aligns with CWE-134 which specifically addresses the use of externally-controlled format strings, making this a well-documented and preventable weakness that requires immediate attention from security teams.
Security teams should conduct comprehensive assessments of their Fortinet deployments to identify all affected devices and prioritize remediation efforts based on risk exposure. Regular vulnerability scanning and monitoring for exploitation attempts should be implemented as ongoing defensive measures. The remediation process should include not only patching but also reviewing and hardening the configuration of affected systems to reduce the attack surface and prevent similar vulnerabilities from being introduced through future development cycles.