Cisco Firepower 2100 Series Security Appliances ARP Denial of Service Vulnerability

published 2020-05-06 6 y ago modified 2026-08-11 2 mo ago also EUVD-2020-24605

cvss: 7.4; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits: 0; none known

A vulnerability in the ARP packet processing of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Security Appliances could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect processing of ARP packets received by the management interface of an affected device. An attacker could exploit this vulnerability by sending a series of unicast ARP packets in a short timeframe that would reach the management interface of an affected device. A successful exploit could allow the attacker to consume resources on an affected device, which would prevent the device from sending internal system keepalives and eventually cause the device to reload, resulting in a denial of service (DoS) condition.

Patch / fix

fixed in 2

cisco secure_firewall_threat_defense 6.6.0
cisco adaptive_security_appliance_software 9.10.1.37, 9.12.3, 9.13.1.2

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 23 mo ago (2024-11-15)

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	7.4	CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD	3.1	7.4	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD	2.0	6.1	AV:A/AC:L/Au:N/C:N/I:N/A:C

Affected products

Cisco Cisco Adaptive Security Appliance (ASA) Software

Classification

Weakness

CWE-399 Resource Management Errors
CWE-400 Uncontrolled Resource Consumption

References

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-fp2100-arp-dos-kLdCK8ks
vendor-advisory

Sources

CVE List CVE-2020-3334
NVD CVE-2020-3334

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary