CVE-2025-20268: Cisco FTD Geolocation Policy Bypass Flaw

CVE-2025-20268 Overview

CVE-2025-20268 is a policy bypass vulnerability in the Geolocation-Based Remote Access (RA) VPN feature of Cisco Secure Firewall Threat Defense (FTD) Software. The flaw allows an unauthenticated, remote attacker to bypass configured geolocation policies that allow or deny HTTP connections based on country or region. The root cause is incomplete parsing of the URL string [CWE-229]. An attacker exploits this by sending a crafted HTTP connection through the affected device, reaching networks that policy should have denied. Cisco published the advisory on August 14, 2025.

Critical Impact
A successful exploit allows unauthenticated remote attackers to bypass geolocation-based HTTP filtering policies, granting access to networks that should be blocked based on source country or region.

Affected Products

Cisco Secure Firewall Threat Defense (FTD) Software
Deployments using the Geolocation-Based Remote Access (RA) VPN feature
Refer to the Cisco Security Advisory for specific affected version ranges

Discovery Timeline

2025-08-14 - CVE-2025-20268 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-20268

Vulnerability Analysis

The vulnerability resides in how Cisco FTD processes HTTP connections traversing the Geolocation-Based Remote Access VPN feature. Administrators configure geolocation policies to allow or deny HTTP traffic based on the source country or region. The FTD software fails to fully parse the URL string before applying policy decisions. This incomplete parsing creates a semantic gap between what the enforcement engine evaluates and what the destination server receives.

An unauthenticated attacker on the network can craft an HTTP request that exploits this parsing inconsistency. The crafted request bypasses the geolocation filter and passes through the device to protected networks. The vulnerability is cataloged under [CWE-229] Improper Handling of Values, reflecting inadequate processing of a request field before policy evaluation. The EPSS probability sits at 0.449%.

Root Cause

The root cause is incomplete URL string parsing within the HTTP inspection path of the Geolocation-Based RA VPN feature. The parser does not fully normalize or interpret the URL, so policy logic evaluates an incomplete representation. Attackers construct request URLs that appear benign to the filter yet still resolve on the backend.

Attack Vector

The attack requires no authentication, no user interaction, and can be executed over the network. The attacker sends a crafted HTTP connection through the targeted FTD device. A successful exploit grants access to HTTP resources that geolocation policy should have blocked. The scope is changed because the bypass affects a resource beyond the vulnerable component itself. No verified proof-of-concept code is publicly available at the time of writing. Refer to the Cisco Security Advisory for technical details.

Detection Methods for CVE-2025-20268

Indicators of Compromise

HTTP requests with unusual URL encoding, fragmented paths, or malformed structure traversing the FTD device
Access log entries showing HTTP sessions from source countries that geolocation policy should deny
Unexpected backend traffic from geographically restricted regions reaching internal HTTP resources

Detection Strategies

Correlate FTD connection events with geolocation policy hit counters to identify requests that reached protected resources despite policy denial
Inspect HTTP request URLs at both the FTD and backend server for parsing divergence
Baseline normal geographic traffic patterns and alert on statistical anomalies in allowed HTTP flows

Monitoring Recommendations

Forward FTD syslog and connection events to a centralized logging platform for retention and correlation
Enable verbose HTTP inspection logging on FTD to capture full URL strings during policy evaluation
Monitor Cisco PSIRT advisories for updated fixed release information tied to this advisory ID

How to Mitigate CVE-2025-20268

Immediate Actions Required

Review the Cisco Security Advisory and identify affected FTD versions in your environment
Upgrade Cisco Secure Firewall Threat Defense Software to a fixed release as specified by Cisco
Audit geolocation-based RA VPN policies and verify enforcement against test traffic from denied regions

Patch Information

Cisco has published a security advisory tracking this issue under the identifier cisco-sa-ftd-ravpn-geobypass-9h38M37Z. Administrators must consult the advisory for the exact fixed software versions applicable to their deployment and follow Cisco upgrade procedures for FTD.

Workarounds

Cisco has not published a documented workaround; upgrading to a fixed release is the supported remediation
Layer additional controls upstream or downstream of FTD, such as web proxy geolocation filtering, until patching completes
Restrict exposure of the RA VPN HTTP-inspecting interface to trusted networks where feasible

bash

# Verify running FTD software version before and after patching
show version

# Review geolocation-based access control policy on FTD
show running-config access-list
show access-list | include geo