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TI-2021-13791 Aliases CVE-2021-34793GHSA-jjpm-mxjp-g6mw

Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software…

Priority MEDIUM 44CWE-924Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00586 48th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco Adaptive Security Appliance (ASA) Softwareall versions—No fix listedCNA
  • Cisco Adaptive Security Appliance (ASA) Software VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 19

CPEVersionsRoleVendor
cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:*before 9.8.4.40VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*before 6.4.0.13; 6.5.0 to before 6.6.5; 6.7.0 to before 6.7.0.3VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*9.9.0 to before 9.12.4.29; 9.13.0 to before 9.14.3.9; 9.15.0 to before 9.15.1.17; 9.16.0 to before 9.16.2.3VulnerableCisco
cpe:2.3:o:cisco:asa_5512-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5512-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5505_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5505:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5515-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5515-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5525-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
  • cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:* Versions before 9.8.4.40 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* Versions before 6.4.0.13; 6.5.0 to before 6.6.5; 6.7.0 to before 6.7.0.3 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions 9.9.0 to before 9.12.4.29; 9.13.0 to before 9.14.3.9; 9.15.0 to before 9.15.1.17; 9.16.0 to before 9.16.2.3 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:asa_5512-x_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5512-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5505_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5505:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5515-x_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5515-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5525-x_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
Show 9 more CPE
CPEVersionsRoleVendor
cpe:2.3:h:cisco:asa_5525-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5545-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5545-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5555-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5555-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5580_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5580:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:o:cisco:asa_5585-x_firmware:009.008\(004.025\):*:*:*:*:*:*:*009.008(004.025)VulnerableCisco
cpe:2.3:h:cisco:asa_5585-x:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
  • cpe:2.3:h:cisco:asa_5525-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5545-x_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5545-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5555-x_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5555-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5580_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5580:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:o:cisco:asa_5585-x_firmware:009.008\(004.025\):*:*:*:*:*:*:* Versions 009.008(004.025) Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asa_5585-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-34793
  2. 2026-10-03 Alias added: GHSA-jjpm-mxjp-g6mw

References

Advisory 1

  • TI-2020-02861 Uncontrolled resource consumption in Cisco Adaptive Security Appliance Software CVSS 3.1HIGH 8.6
  • TI-2021-17312 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SSL/TLS Denial of Service Vulnerability CVSS 3.1HIGH 8.6
  • TI-2020-03115 Uncontrolled resource consumption in Cisco Adaptive Security Appliance Software CVSS 3.1HIGH 8.6
  • TI-2020-03075 Uncontrolled resource consumption in Cisco Adaptive Security Appliance Software CVSS 3.1HIGH 8.6
  • TI-2020-02985 Unrestricted file upload in Cisco Adaptive Security Appliance Software CVSS 3.1HIGH 8.6
  • TI-2021-17313 Stack-based buffer overflow in Cisco Adaptive Security Appliance Software CVSS 3.1HIGH 8.6
See all 62 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences