CVE intelligence and bounded remediation

CVE-2024-20494 — Cisco Adaptive Security Appliance Software security vulnerability

High CVSS 8.6

A vulnerability in the TLS cryptography functionality of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper data validation during the TLS 1.3 handshake. An attacker could exploit this vulnerability by sending a crafted TLS 1.3 packet to an affected system through a TLS 1.3-enabled listening socket. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: This vulnerability can also impact the integrity of a device by causing VPN HostScan communication failures or file transfer failures when Cisco ASA Software is upgraded using Cisco Adaptive Security Device Manager (ASDM).

Severity
High
CVSS
8.6 (3.1)
Published
2024-10-23
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-1287

Affected products

  • cisco / adaptive_security_appliance_software / 9.19.1
  • cisco / adaptive_security_appliance_software / 9.19.1.5
  • cisco / adaptive_security_appliance_software / 9.19.1.9
  • cisco / adaptive_security_appliance_software / 9.19.1.12
  • cisco / adaptive_security_appliance_software / 9.19.1.18
  • cisco / adaptive_security_appliance_software / 9.19.1.22

Showing 6 representative product identities from 25 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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