CVE-2019-1867
📋 TL;DR
This vulnerability allows unauthenticated remote attackers to bypass authentication on Cisco Elastic Services Controller's REST API, enabling them to execute arbitrary administrative actions. It affects Cisco ESC systems with vulnerable REST API endpoints exposed. Organizations running affected Cisco ESC versions are at risk.
💻 Affected Systems
- Cisco Elastic Services Controller
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to deploy malicious services, exfiltrate sensitive data, or disrupt network operations with administrative privileges.
Likely Case
Unauthorized access to ESC management functions, potential service disruption, and configuration changes affecting network services.
If Mitigated
Limited impact if API endpoints are not internet-facing and network segmentation restricts access to management interfaces.
🎯 Exploit Status
Crafted HTTP requests to REST API endpoints can bypass authentication without special tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: ESC 4.3.0.112 or 4.4.0.75 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190507-esc-authbypass
Restart Required: Yes
Instructions:
1. Download appropriate patch from Cisco Software Center. 2. Backup current configuration. 3. Apply patch following Cisco ESC upgrade procedures. 4. Restart ESC services.
🔧 Temporary Workarounds
Network Access Control
allRestrict network access to ESC REST API endpoints using firewall rules or network segmentation.
Disable Unused API Endpoints
linuxDisable REST API if not required for operations.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate ESC management interfaces
- Deploy web application firewall with authentication bypass detection rules
🔍 How to Verify
Check if Vulnerable:
Check ESC version via web interface or CLI. Versions below 4.3.0.112 or 4.4.0.75 are vulnerable.Check Version:
ssh admin@esc-host show versionVerify Fix Applied:
Verify version is 4.3.0.112 or higher, or 4.4.0.75 or higher. Test authentication requirements on REST API endpoints.📡 Detection & Monitoring
Log Indicators:
- Unauthenticated API requests succeeding
- Administrative actions from unexpected IP addresses
- Failed authentication attempts followed by successful requests
Network Indicators:
- HTTP requests to /restconf/ endpoints without authentication headers
- Unusual API call patterns from external sources
SIEM Query:
source="esc-logs" AND (event_type="api_call" AND auth_status="success" AND src_ip NOT IN allowed_management_ips)