CISCO Security Advisory
Published Date: Not specified
CVE: CVE-2024-20260
Advisory Summary
🔷 Cisco Secure Firewall ASA/FTD: SSL VPN DoS via Memory Exhaustion (High Risk)
⚠️ What’s happening
Cisco has updated an advisory describing a Denial of Service (DoS) vulnerability impacting VPN and management web servers on Cisco Secure Firewall ASA Software and Cisco Secure Firewall Threat Defense (FTD) Software. The issue affects SSL VPN connection handling—an attacker can exhaust system memory or buffer blocks, causing SSL VPN processing to slow dramatically and eventually stop.
🚨 Why it matters (threat scenario)
An unauthenticated remote attacker can trigger the condition by sending a large number of new incoming SSL/TLS connections to the targeted device. Once resources are depleted, service recovery may be slow, and a manual reload could be required for rapid restoration.
🧩 Affected scope (key update)
The advisory was originally scoped to virtual platforms (ASAv and FTDv) but later expanded—all Cisco Secure Firewall ASA and FTD software platforms are impacted.
🛠️ Fix / Remediation
✅ Cisco released software updates that address the vulnerability.
🚫 No workarounds are available for this issue.
🔐 Actionable next steps for security & operations teams
1. Identify exposure: confirm whether your ASA/FTD deployments run affected software versions.
2. Plan upgrades: schedule installation of the patched Cisco software update(s) from the advisory.
3. Assess SSL VPN resilience: ensure you have monitoring/alerting for SSL VPN session handling failures and resource exhaustion indicators.
4. Operational readiness: prepare a reload/rollback plan (as service may require manual intervention in worst cases).
- CVE: CVE-2024-20260
- Impact rating: High
-2024-20260
Reference: Vendor Advisory