Cyber Resilience

CVE-2023-20006

Cisco Secure Firewall Threat Defense 7.2.1 … 7.2.3

Published
28 June 2023
Modified
11 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0092 57th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2023-20006 is a high-severity Incorrect Conversion between Numeric Types (CWE-681) vulnerability in Cisco Secure Firewall Threat Defense. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 43% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A vulnerability in the hardware-based SSL/TLS cryptography functionality of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause an affected device to…

more

reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to an implementation error within the cryptographic functions for SSL/TLS traffic processing when they are offloaded to the hardware. An attacker could exploit this vulnerability by sending a crafted stream of SSL/TLS traffic to an affected device. A successful exploit could allow the attacker to cause an unexpected error in the hardware-based cryptography engine, which could cause the device to reload.

CWE(s)
CWE-681

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-20330Same product: Cisco Firepower 2110
CVE-2023-20244Same product: Cisco Firepower 2110
CVE-2024-20408Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20022Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20494Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20049Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20402Same product: Cisco Adaptive Security Appliance Software
CVE-2025-20333Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20100Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20024Same product: Cisco Adaptive Security Appliance Software

Affected Assets

cisco
secure firewall threat defense
7.2.1, 7.2.2, 7.2.3
cisco
adaptive security appliance software
9.16.4, 9.18.2, 9.18.2.5

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require code reviews, static analysis, and developer training that catch and prevent numeric type-conversion errors.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect numeric conversion defects before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes type-safety and conversion checks that reduce numeric truncation risks.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate safe numeric handling and range validation.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles promote strong typing and safe conversion practices.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address correct numeric type conversions and overflow checks.

References