Home/CVE/A vulnerability in SSL/TLS message handler for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Thre
CVE

CVE-2021-40117

A vulnerability in SSL/TLS message handler for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Thre

A vulnerability in SSL/TLS message handler for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because incoming SSL/TLS packets are not properly processed. An attacker could exploit this vulnerability by sending a crafted SSL/TLS packet to an affected device.

A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

HIGH · CVSS 8.6 EPSS 0.00409
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-400Uncontrolled Resource Consumption
▤

Affected Products & Versions

18
cisco adaptive security appliance< 9.8.4.40
cisco firepower threat defense< 6.2.3.17
cisco firepower threat defense>= 6.3.0 and < 6.4.0.13
cisco firepower threat defense>= 6.5.0 and < 6.6.5
cisco firepower threat defense>= 6.7.0 and < 6.7.0.3
cisco firepower threat defense>= 7.0.0 and < 7.0.1
cisco adaptive security appliance software>= 9.9.0 and < 9.12.4.26
cisco adaptive security appliance software>= 9.13.0 and < 9.14.3.9
▣

Scoring & Timeline

8.6
HIGH · CVSS v3.1 · psirt@cisco.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD27 Oct 2021 · 07:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

1
cisco-csafcisco-sa-asaftd-dos-4ygzLKU9
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dos-4ygzLKU9Vendor Advisory
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