CVE-2025-20363
📋 TL;DR
This critical vulnerability allows remote attackers to execute arbitrary code with root privileges on affected Cisco devices. Unauthenticated attackers can exploit Cisco ASA/FTD devices, while authenticated low-privilege users can exploit Cisco IOS/IOS XE/IOS XR devices. The vulnerability stems from improper input validation in HTTP requests.
💻 Affected Systems
- Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Secure Firewall Threat Defense (FTD) Software
- Cisco IOS Software
- Cisco IOS XE Software
- Cisco IOS XR Software
📦 What is this software?
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Adaptive Security Appliance Software by Cisco
View all CVEs affecting Adaptive Security Appliance Software →
Ios by Cisco
Ios Xe by Cisco
Cisco IOS XE is Cisco's modern network operating system running on enterprise routers, switches, and wireless controllers deployed across corporate networks, data centers, branch offices, and service provider infrastructure worldwide. As the evolution of Cisco IOS, IOS XE provides a Linux-based modu...
Learn more about Ios Xe →Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
Ios Xr by Cisco
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to network infiltration, data exfiltration, and persistent backdoor installation
Likely Case
Device takeover enabling lateral movement, credential harvesting, and service disruption
If Mitigated
Limited impact if web services are disabled or properly segmented
🎯 Exploit Status
Exploitation requires crafting specific HTTP requests and may need additional system information or bypassing exploit mitigations
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Cisco advisory for specific fixed versions per product
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-http-code-exec-WmfP3h3O
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions 2. Download appropriate fixed software 3. Backup configuration 4. Apply patch during maintenance window 5. Verify patch installation
🔧 Temporary Workarounds
Disable HTTP/HTTPS services
allDisable web management interfaces if not required
no http server enable
no ip http server
no ip http secure-server
Restrict access with ACLs
allLimit web service access to trusted management networks only
ip http access-class <ACL-NUMBER>
ip http secure-server access-class <ACL-NUMBER>
🧯 If You Can't Patch
- Disable all web management services immediately
- Implement strict network segmentation and firewall rules to limit access to management interfaces
🔍 How to Verify
Check if Vulnerable:
Check device version against affected versions in Cisco advisoryCheck Version:
show version | include VersionVerify Fix Applied:
Verify installed version matches fixed version from Cisco advisory📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to management interfaces
- Multiple failed authentication attempts followed by successful access
- Unexpected process execution or configuration changes
Network Indicators:
- HTTP requests with unusual payloads to device management ports
- Traffic from unexpected sources to management interfaces
SIEM Query:
source="cisco-asa" OR source="cisco-ios" (http_request OR web_access) AND (payload_size>threshold OR suspicious_user_agent)