CVE-2021-34793

A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
8.6 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
ciscoCNA
8.6 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVEADP
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CISA-ADPADP
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Base Score
CVSS 3.x
EPSS Score
Percentile: 27%
VendorProductVersion
ciscoadaptive_security_appliance
𝑥
< 9.8.4.40
ciscofirepower_threat_defense
𝑥
< 6.4.0.13
ciscofirepower_threat_defense
6.5.0 ≤
𝑥
< 6.6.5
ciscofirepower_threat_defense
6.7.0 ≤
𝑥
< 6.7.0.3
ciscoadaptive_security_appliance_software
9.9.0 ≤
𝑥
< 9.12.4.29
ciscoadaptive_security_appliance_software
9.13.0 ≤
𝑥
< 9.14.3.9
ciscoadaptive_security_appliance_software
9.15.0 ≤
𝑥
< 9.15.1.17
ciscoadaptive_security_appliance_software
9.16.0 ≤
𝑥
< 9.16.2.3
ciscoasa_5512-x_firmware
009.008\(004.025\)
ciscoasa_5505_firmware
009.008\(004.025\)
ciscoasa_5515-x_firmware
009.008\(004.025\)
ciscoasa_5525-x_firmware
009.008\(004.025\)
ciscoasa_5545-x_firmware
009.008\(004.025\)
ciscoasa_5555-x_firmware
009.008\(004.025\)
ciscoasa_5580_firmware
009.008\(004.025\)
ciscoasa_5585-x_firmware
009.008\(004.025\)
𝑥
= Vulnerable software versions