CVE•Published 2023-11-01•Modified 2026-08-11•1 article on news•5 live references•NVD data

CVE-2023-20083Cisco · Secure_firewall_threat_defense

Vulnerability data via NVD (ingested)

CVSS v3.1
8.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS percentile
49
Exploit Prediction Scoring System · top 51% of all CVEs
Description

A vulnerability in ICMPv6 inspection when configured with the Snort 2 detection engine for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the CPU of an affected device to spike to 100 percent, which could stop all traffic processing and result in a denial of service (DoS) condition. FTD management traffic is not affected by this vulnerability. This vulnerability is due to improper error checking when parsing fields within the ICMPv6 header. An attacker could exploit this vulnerability by sending a crafted ICMPv6 packet through an affected device. A successful exploit could allow the attacker to cause the device to exhaust CPU resources and stop processing traffic, resulting in a DoS condition. Note: To recover from the DoS condition, the Snort 2 Detection Engine or the Cisco FTD device may need to be restarted.

Timeline
Published 2023-11-01
Modified 2026-08-11

External references

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

More intel sources (5)

Known PoCs on GitHub (2)