CVE-2022-29056 in FortiMail
Summary
by MITRE • 03/09/2023
A improper restriction of excessive authentication attempts vulnerability [CWE-307] in Fortinet FortiMail version 6.4.0, version 6.2.0 through 6.2.4 and before 6.0.9 allows a remote unauthenticated attacker to partially exhaust CPU and memory via sending numerous HTTP requests to the login form.
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Analysis
by VulDB Data Team • 04/02/2023
The vulnerability identified as CVE-2022-29056 represents a critical weakness in Fortinet FortiMail's authentication mechanism that falls under the CWE-307 category of improper restriction of excessive authentication attempts. This flaw affects multiple versions of the FortiMail email security appliance, specifically targeting versions 6.4.0, 6.2.0 through 6.2.4, and versions prior to 6.0.9. The vulnerability stems from insufficient rate limiting and authentication attempt controls within the web interface's login form, creating a pathway for malicious actors to exploit the system's resource management capabilities.
The technical implementation of this vulnerability allows a remote unauthenticated attacker to perform a denial of service attack by flooding the system with numerous HTTP requests directed at the login form endpoint. This excessive request pattern causes the FortiMail appliance to consume disproportionate amounts of CPU cycles and memory resources as it processes each authentication attempt. The flaw does not require any valid credentials or prior access to the system, making it particularly dangerous as it can be exploited by anyone with network access to the appliance's web interface.
From an operational impact perspective, this vulnerability significantly undermines the availability and performance of the FortiMail appliance, potentially disrupting email services for organizations that rely on the system for their communication infrastructure. The partial exhaustion of CPU and memory resources can lead to degraded performance, system instability, and in severe cases, complete service disruption. Organizations may experience delays in email processing, failed authentication attempts, and overall system responsiveness issues that can affect business operations and communication workflows.
The attack vector for this vulnerability aligns with common network-based exploitation techniques and represents a form of resource exhaustion attack that can be executed with minimal technical expertise. Security professionals should consider this vulnerability in their threat modeling exercises and recognize it as a potential indicator of broader system compromise attempts. The vulnerability's classification under CWE-307 emphasizes the importance of implementing proper authentication controls and rate limiting mechanisms to prevent such attacks from succeeding.
Mitigation strategies for this vulnerability should include immediate implementation of rate limiting controls on the web interface login endpoints, enabling proper authentication attempt throttling, and deploying network-level controls to restrict excessive requests from single IP addresses. Organizations should also ensure their FortiMail appliances are updated to the latest supported versions that contain patches addressing this specific weakness. The implementation of intrusion detection systems and monitoring solutions can help detect unusual authentication patterns and alert security teams to potential exploitation attempts. Additionally, organizations should review their network segmentation practices to limit direct access to administrative interfaces and consider implementing additional authentication layers to reduce the attack surface for such vulnerabilities.