TIRESIS/Forecast/CVE-2025-6599
MEDIUM RISK

CVE-2025-6599

An uncontrolled resource consumption vulnerability in the web server of Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an attacker to perform Slowloris‑style denial‑of‑service (DoS) attacks. Such attacks may temporarily block legitimate HTTP requests an…

SMB Attack Probability Score
23/100medium
Weighted: EPSS · CISA KEV · SMB stack prevalence · exploit maturity · CVSS vector
CVSS v3
5.3
EPSS (30d)
0.06%
SMB Exposure
54.8/100
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
🔓
SMB Impact
How this vulnerability affects a real small business
1
How this breaks an SMB

Firewall or VPN compromise gives attackers full internal network access — no further credentials needed. All connected systems are immediately at risk.

2
Typical real-world scenario

Automated scanner identifies the exposed appliance. Within hours, lateral movement begins: file servers, domain controller, and backup systems are reached.

3
Estimated downtime & cost
Est. downtime
3–7 days
Business cost range
€15K–€80K
4
What IT should check this week
Is this appliance directly internet-facing?
Is firmware/OS version patched to latest?
Are admin consoles accessible without MFA?
Is network segmentation between IT and OT/servers active?
Scenarios are generated based on software category and CVE characteristics. Cost ranges reflect SMB incidents in TIRESIS incident database.
Threat Evolution Timeline
From disclosure to predicted exploitation — 3 events
◈ 1 predicted
📋
18 Nov 2025
Vulnerability disclosed
CVE published by NVD with CVSS 5.3 (MEDIUM)
📍
TODAY
Today
EPSS: 0.1% probability of exploitation in next 30 days. SMB Risk Score: 23/100
Forecast →
✅
29 Jun 2026◈ predicted · in 60 days
Predicted: widespread patch adoption
Low EPSS suggests limited active exploitation. Most organizations expected to patch in routine maintenance cycle.
◈ Predicted eventsare estimates based on EPSS score, exploit maturity, and historical CVE progression patterns. They are not guaranteed outcomes.
Affected Products
vmg4005-b50bwx5610-b0ex5401-b1nebula fwa505emg5523-t50bnr5309 firmwarevmg3927-t50k firmwarevmg8623-t50bemg3525-t50b firmwarevmg8825-t50k firmwarewx3401-b0 firmwarewx3401-b1vmg8623-t50b firmwarenebula fwa510 firmwaredx5401-b0px5301-t0 firmwareex3301-t0 firmwarenebula fwa515 firmwareex3500-t0ex5601-t0 firmwaredm4200-b0vmg4005-b50b firmwareax7501-b1ex5510-b0 firmware
Remediation & References
What to do
🌐No authentication required — restrict external access nowhigh

This vulnerability can be exploited remotely without credentials or user interaction. Until patched: block access to the affected service from the internet using firewall rules or ACLs. Only allow access from trusted IPs.

🔥Apply firewall firmware update via vendor PSIRT advisoryhigh

Firewall vulnerabilities are high-value targets — they sit at the network perimeter. Download the patched firmware from the vendor's official PSIRT page. Schedule an off-hours maintenance window to avoid business disruption during the update.

⚙️Disable management interface access from the internetmedium

The firewall management portal (web UI, SSH, API) should never be exposed directly to the internet. Restrict management access to internal IPs or a dedicated management VLAN only.

NVD Full Entry ↗Official vulnerability detail, CVSS vectors, CPE listEPSS Score ↗Exploit Prediction Scoring System — FIRST.orgMitre CVE ↗MITRE CVE Program official entry
Vendor & Exploit References
Scoring Methodology

SMB Attack Probability Score weights: EPSS exploit likelihood (35%), CISA KEV active exploitation (25%), SMB stack prevalence (20%), exploit maturity (10%), CVSS network vector complexity (10%). Impact scenarios are derived from software category and historical SMB incident patterns. Scores recompute daily.