CVE-2025-59459
📋 TL;DR
An attacker with SSH access to an unprivileged account can disrupt services including SSH itself, causing persistent denial of service. This affects systems running vulnerable versions of the software with SSH enabled. The vulnerability requires initial access to a low-privilege SSH account.
💻 Affected Systems
- SICK industrial devices and software
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete loss of SSH service and other critical services, requiring physical access or console to restore availability.
Likely Case
Temporary service disruption affecting SSH and other services until manual intervention.
If Mitigated
Minimal impact with proper access controls and monitoring in place.
🎯 Exploit Status
Requires authenticated SSH access to an unprivileged account first.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched versions.
Vendor Advisory: https://www.sick.com/.well-known/csaf/white/2025/sca-2025-0013.json
Restart Required: No
Instructions:
1. Review vendor advisory for affected versions. 2. Apply vendor-provided patches or firmware updates. 3. Verify SSH service functionality post-update.
🔧 Temporary Workarounds
Restrict SSH Access
allLimit SSH access to trusted IPs and users only.
Configure firewall rules to restrict SSH port (typically 22) to management networks.
Use SSH key authentication only and disable password auth.
Implement Least Privilege
allRemove or restrict unprivileged SSH accounts.
Review and disable unnecessary SSH user accounts.
Implement role-based access control for SSH users.
🧯 If You Can't Patch
- Segment network to isolate vulnerable devices from untrusted networks.
- Implement strict monitoring and alerting for SSH access attempts and service disruptions.
🔍 How to Verify
Check if Vulnerable:
Check device firmware/software version against vendor advisory list.Check Version:
Device-specific; typically via SSH command or web interface (e.g., 'show version' or similar).Verify Fix Applied:
Verify installed version matches patched version from vendor advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual SSH login patterns from unprivileged accounts.
- Service disruption logs (e.g., SSH daemon crashes, service restarts).
Network Indicators:
- Increased SSH connection attempts to unprivileged accounts.
- Unexpected service outages following SSH access.
SIEM Query:
source="ssh_logs" AND (event="service_stop" OR event="crash") AFTER successful_auth🔗 References
- https://sick.com/psirt
- https://www.cisa.gov/resources-tools/resources/ics-recommended-practices
- https://www.first.org/cvss/calculator/3.1
- https://www.sick.com/.well-known/csaf/white/2025/sca-2025-0013.json
- https://www.sick.com/.well-known/csaf/white/2025/sca-2025-0013.pdf
- https://www.sick.com/media/docs/9/19/719/special_information_sick_operating_guidelines_cybersecurity_by_sick_en_im0106719.pdf
