CVE-2025-49813 Overview
CVE-2025-49813 is an OS Command Injection vulnerability [CWE-78] affecting Fortinet FortiADC. The flaw stems from improper neutralization of special elements in HTTP parameters processed by the appliance. An authenticated attacker with low privileges can send specifically crafted HTTP parameters to execute unauthorized code on the underlying operating system. The vulnerability affects FortiADC version 7.2.0 and versions before 7.1.1. Fortinet published the advisory FG-IR-25-501 on August 12, 2025.
Critical Impact
Authenticated attackers can execute arbitrary OS commands on FortiADC appliances, compromising the confidentiality, integrity, and availability of application delivery infrastructure.
Affected Products
- Fortinet FortiADC 7.2.0
- Fortinet FortiADC versions before 7.1.1
- Fortinet FortiADC application delivery controller appliances
Discovery Timeline
- 2025-08-12 - CVE-2025-49813 published to NVD
- 2025-08-12 - Fortinet releases security advisory FG-IR-25-501
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-49813
Vulnerability Analysis
CVE-2025-49813 is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command. The vulnerability resides in FortiADC's HTTP parameter handling logic. The affected code path passes user-supplied input into shell command execution without adequate sanitization or escaping of shell metacharacters.
Successful exploitation grants command execution in the context of the FortiADC service. FortiADC operates as an application delivery controller responsible for load balancing, SSL offloading, and web application security. Compromise of the appliance exposes traffic passing through it and provides a pivot point into internal networks.
The attack surface requires authentication with low privileges, which limits opportunistic attacks. However, credentials for management interfaces are frequently exposed through phishing, credential stuffing, or lateral movement from adjacent compromised systems.
Root Cause
The root cause is missing input validation on HTTP parameters that flow into an OS command invocation. Shell metacharacters such as ;, |, &, and backticks are not neutralized before the input is concatenated into a command string. This design allows the attacker to append or inject additional commands executed by the system shell.
Attack Vector
The attack vector is network-based against the FortiADC management interface. An attacker authenticates with a low-privilege account, then submits a crafted HTTP request containing malicious parameters. The parameters carry embedded shell syntax that breaks out of the intended command context. The scope remains unchanged, but the impact on confidentiality, integrity, and availability is high because commands execute with the privileges of the FortiADC service.
No public proof-of-concept or exploit code is currently available. See the Fortinet Security Advisory FG-IR-25-501 for vendor technical details.
Detection Methods for CVE-2025-49813
Indicators of Compromise
- Unexpected outbound network connections originating from FortiADC management interfaces to unknown external hosts.
- Presence of shell metacharacters (;, |, &, backticks, $()) in HTTP request parameters logged by the FortiADC web management interface.
- New or modified files on the appliance filesystem outside of scheduled configuration changes or firmware upgrades.
- Anomalous administrative process execution or child processes spawned by the FortiADC web daemon.
Detection Strategies
- Inspect FortiADC access logs for POST or GET requests containing encoded command separators in parameter values.
- Correlate authentication events for low-privilege administrator accounts with subsequent configuration or system activity.
- Deploy network monitoring to identify unusual traffic patterns from FortiADC appliances toward internal or external endpoints.
Monitoring Recommendations
- Forward FortiADC syslog and audit events to a centralized SIEM for correlation and long-term retention.
- Alert on any administrative session originating from unexpected source IP ranges or geolocations.
- Track process execution and file integrity on the appliance where the platform supports such telemetry.
How to Mitigate CVE-2025-49813
Immediate Actions Required
- Upgrade FortiADC to a fixed release as specified in Fortinet advisory FG-IR-25-501.
- Restrict management interface access to trusted administrative networks using ACLs or dedicated management VLANs.
- Rotate all administrator credentials and review account privileges to enforce least privilege.
- Audit recent administrative activity for signs of unauthorized parameter tampering.
Patch Information
Fortinet has released fixed versions of FortiADC. Administrators should consult the Fortinet Security Advisory FG-IR-25-501 for the specific fixed builds and upgrade path applicable to their deployment. Apply the vendor-supplied firmware update through the standard FortiADC upgrade procedure.
Workarounds
- Disable or restrict access to the HTTP management interface until the patch is applied.
- Enforce multi-factor authentication for all administrative accounts on FortiADC.
- Implement network segmentation to isolate FortiADC management planes from user and production networks.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
