PT-2021-5001 · Cisco · Cisco Asa+1

Published 2021-10-27 · Updated 2023-08-16 · CVE-2021-34793

Positive Technologies (AI Summary)

CVSS v3.1

8.6

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software (affected versions not specified)

Description 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.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

Weakness Enumeration

CWE-924

Related Identifiers

BDU:2021-05766

CVE-2021-34793

Affected Products

Cisco Asa

Firepower Threat Defense

References · 9

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dos-JxYWMJyL · Vendor Advisory
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dos-JxYWMJyL · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-34793 · Security Note
• https://bdu.fstec.ru/vul/2021-05766 · Security Note
• https://osv.dev/vulnerability/CVE-2021-34793 · Vendor Advisory
• https://safe-surf.ru/specialists/bulletins-nkcki/671527 · Security Note
• https://cybersecurity-help.cz/vdb/SB2021102803 · Note
• https://t.me/cibsecurity/31310 · Telegram Post
• https://t.me/cvenotify/22511 · Telegram Post