CVE-2026-30897 in FortiWeb
Summary
by MITRE • 03/10/2026
A stack-based buffer overflow vulnerability in Fortinet FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4.0 through 7.4.11, FortiWeb 7.2 all versions, FortiWeb 7.0 all versions may allow a remote authenticated attacker who can bypass stack protection and ASLR to execute arbitrary code or commands via crafted HTTP requests.
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Analysis
by VulDB Data Team • 03/13/2026
This vulnerability represents a critical stack-based buffer overflow in Fortinet FortiWeb web application firewalls across multiple version ranges, including 8.0.0 through 8.0.3, 7.6.0 through 7.6.6, 7.4.0 through 7.4.11, and all versions of 7.2 and 7.0 series. The flaw exists in the HTTP request processing functionality where insufficient input validation allows attackers to manipulate stack memory through carefully crafted HTTP requests. This vulnerability is particularly dangerous because it can be exploited by authenticated attackers who have bypassed stack protection mechanisms and address space layout randomization, indicating a sophisticated attack vector that leverages advanced exploitation techniques. The buffer overflow occurs when the system processes malformed HTTP headers or request parameters without proper bounds checking, leading to memory corruption that can be leveraged for arbitrary code execution.
The technical implementation of this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which occurs when a program writes data beyond the boundaries of a fixed-length stack buffer. In FortiWeb's case, the issue manifests during HTTP request parsing where the application fails to validate the length of incoming data against the allocated buffer space. This allows an attacker to overwrite adjacent stack memory locations including return addresses, function pointers, and other critical control data. The exploitation requires an authenticated session, suggesting that the vulnerability may be triggered through legitimate administrative or user access points, making it particularly concerning for organizations where privileged accounts are compromised. The attack vector specifically targets HTTP request processing, indicating that the vulnerability exists in the web server component or its associated parsing libraries.
The operational impact of this vulnerability extends beyond simple code execution to potentially enable complete system compromise and persistent access within the network environment. Successful exploitation could allow an attacker to gain administrative privileges on the FortiWeb appliance, potentially leading to data exfiltration, network reconnaissance, and lateral movement throughout the protected network. The vulnerability affects multiple major version lines of FortiWeb, indicating a widespread issue that impacts organizations relying on these security appliances for web application protection. Organizations using affected versions face significant risk of unauthorized access to their web applications and infrastructure, as the FortiWeb appliance serves as a critical security control for protecting web applications from various threats including SQL injection, cross-site scripting, and other web-based attacks.
Organizations should prioritize immediate patching of all affected FortiWeb versions to mitigate this vulnerability, as the combination of authenticated access and stack overflow capabilities creates a high-severity threat. The mitigation strategy should include implementing network segmentation to limit access to FortiWeb appliances, deploying additional monitoring for suspicious HTTP traffic patterns, and ensuring that only authorized personnel have administrative access to these devices. Security teams should also conduct thorough network scans to identify all instances of affected FortiWeb versions and implement proper access controls and privilege management. Given the potential for persistent backdoor access through this vulnerability, organizations should also consider performing comprehensive security audits and network forensics to detect any potential compromise of their web application security infrastructure. The vulnerability's classification under CWE-121 and potential exploitation through established attack patterns aligns with techniques documented in the ATT&CK framework, specifically related to privilege escalation and persistence mechanisms that attackers may employ when exploiting buffer overflow vulnerabilities in web security appliances.