CVE-2026-0517
📋 TL;DR
CVE-2026-0517 is a denial-of-service vulnerability in Secure Access Server where an attacker can crash the server by sending a specially crafted packet. This affects all systems running Secure Access Server versions prior to 14.20, potentially disrupting legitimate user access to the service.
💻 Affected Systems
- Secure Access Server
📦 What is this software?
Secure Access by Absolute
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage of the Secure Access Server, preventing all legitimate users from accessing protected resources until manual restart.
Likely Case
Temporary service disruption affecting multiple users, requiring administrator intervention to restart the server.
If Mitigated
Minimal impact with proper network segmentation and monitoring allowing quick detection and response.
🎯 Exploit Status
Exploitation requires only network access to the server and ability to send specially crafted packets.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 14.20 or later
Vendor Advisory: https://www.absolute.com/platform/security-information/vulnerability-archive/cve-2026-0517
Restart Required: Yes
Instructions:
1. Download Secure Access Server version 14.20 or later from vendor portal. 2. Backup current configuration. 3. Install the updated version following vendor documentation. 4. Restart the Secure Access Server service.
🔧 Temporary Workarounds
Network Access Control
allRestrict network access to Secure Access Server to only trusted IP addresses/networks
Use firewall rules to limit access: iptables -A INPUT -p tcp --dport [SERVER_PORT] -s [TRUSTED_NETWORK] -j ACCEPT
iptables -A INPUT -p tcp --dport [SERVER_PORT] -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Secure Access Server from untrusted networks
- Deploy network-based intrusion detection/prevention systems to detect and block DoS attempts
🔍 How to Verify
Check if Vulnerable:
Check Secure Access Server version via admin interface or configuration files. If version is below 14.20, system is vulnerable.Check Version:
Check vendor-specific documentation for version command, typically available in admin console or via 'sasadmin --version'Verify Fix Applied:
Verify version is 14.20 or higher after update and test server functionality remains operational.📡 Detection & Monitoring
Log Indicators:
- Unexpected server crashes or restarts
- Connection spikes followed by service unavailability
- Error logs indicating malformed packet processing
Network Indicators:
- Unusual traffic patterns to Secure Access Server port
- Multiple connection attempts with malformed packets
SIEM Query:
source="secure_access_server" AND (event_type="crash" OR event_type="restart") OR (packet_size>threshold AND dest_port=[SERVER_PORT])