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TI-2021-13704 Aliases CVE-2021-34704GHSA-25qg-5w5q-f6xw

Stack-based buffer overflow in Cisco Adaptive Security Appliance Software

Priority MEDIUM 46CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01362 71st percentileScored 2026-11-07
Fix Fixed Cisco Adaptive Security Appliance Software (Cisco): 6.4.0.13Cisco Firepower Threat Defense Software (Cisco): 6.6.5

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 Softwarebefore 6.4.0.136.4.0.13Patch availableCNA
CiscoCisco Firepower Threat Defense Softwarebefore 6.6.56.6.5Patch availableCNA
  • Cisco Adaptive Security Appliance Software VendorCisco Affected before 6.4.0.13 Fixed in 6.4.0.13 Patch available CNA
  • Cisco Firepower Threat Defense Software VendorCisco Affected before 6.6.5 Fixed in 6.6.5 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*6.7.0 to before 6.7.0.3VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:*7.0.0VulnerableCisco
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*9.15 to before 9.15.1.17; 9.16 to before 9.16.2VulnerableCisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* Versions 6.7.0 to before 6.7.0.3 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:* Versions 7.0.0 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions 9.15 to before 9.15.1.17; 9.16 to before 9.16.2 Vulnerable ·Cisco

Remediation

  • Fix · CNA Cisco Adaptive Security Appliance Software (Cisco) Fixed in 6.4.0.13
  • Fix · CNA Cisco Firepower Threat Defense Software (Cisco) Fixed in 6.6.5

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Cisco Adaptive Security Appliance Software, Cisco Firepower Threat Defense Software 6.4.0.13, 6.6.5

    2 records Highest priority Priority MEDIUM 2 MEDIUM

    Other records, highest priority first

    • TI-2021-01297 Stack-based buffer overflow in Cisco Adaptive Security Appliance SoftwarePriority MEDIUM 46
    Show all 2 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-34704
  2. 2026-10-03 Alias added: GHSA-25qg-5w5q-f6xw

References

Advisory 1

  • TI-2025-14628 Buffer overflow in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.9
  • TI-2016-05454 Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on… KEVCVSS 3.1HIGH 8.8
  • TI-2023-06973 Authentication bypass in Cisco Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.1
  • TI-2026-82192 Denial of service in Cisco Secure Firewall ASA and FTD SSL VPN KEVCVSS 3.1HIGH 8.6
  • TI-2026-16533 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense… KEVCVSS 3.1HIGH 8.6
  • TI-2025-14657 Missing authorization in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1HIGH 8.6
See all 354 →

Sources

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