Cyber Resilience

CVE-2024-20293

Cisco Adaptive Security Appliance Software 9.19.1 – 9.19.1.24

Published
22 May 2024
Modified
11 August 2026
Patch / advisory
CVSS Score v3.1 5.8
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:L/A:N
EPSS Score 0.0040 32th percentile
Risk Priority 46 floored blend · peak EPSS

Summary

CVE-2024-20293 is a medium-severity Interpretation Conflict (CWE-436) vulnerability in Cisco Adaptive Security Appliance Software. Its CVSS base score is 5.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in the activation of an access control list (ACL) on Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the protection that is offered by a…

more

configured ACL on an affected device. This vulnerability is due to a logic error that occurs when an ACL changes from inactive to active in the running configuration of an affected device. An attacker could exploit this vulnerability by sending traffic through the affected device that should be denied by the configured ACL. The reverse condition is also true—traffic that should be permitted could be denied by the configured ACL. A successful exploit could allow the attacker to bypass configured ACL protections on the affected device, allowing the attacker to access trusted networks that the device might be protecting. Note: This vulnerability applies to both IPv4 and IPv6 traffic as well as dual-stack ACL configurations in which both IPv4 and IPv6 ACLs are configured on an interface.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20069Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20268Same product: Cisco Adaptive Security Appliance Software
CVE-2023-20275Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20025Same product: Cisco Adaptive Security Appliance Software
CVE-2023-20247Same product: Cisco Adaptive Security Appliance Software
CVE-2018-0101Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20408Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20022Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20341Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20494Same product: Cisco Adaptive Security Appliance Software

Affected Assets

cisco
adaptive security appliance software
9.20.1, 9.20.1.5 · 9.19.1 — 9.19.1.24
cisco
secure firewall threat defense
7.3.0 — 7.4.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover cases where two products interpret the same inputs or state transitions differently.

Strict, consistently applied input validation reduces the chance that one product will accept data the other product rejects or interprets differently.

Applying security engineering principles during design can require unambiguous protocol and data-format specifications that eliminate divergent interpretations between products.

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 reduce the chance of introducing parser or state-machine inconsistencies.

DE.AE-03 partial match
prevents

Correlating logs from multiple products can surface discrepancies caused by interpretation conflicts.

DE.CM-09 partial match
prevents

Runtime monitoring of software behavior can detect adverse outcomes stemming from differing interpretations.

GV.SC-07 partial match
prevents

Supplier risk assessments can identify products whose differing interpretations create systemic exposure.

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.

finds

Security testing can detect and correct cases where one component misinterprets another’s state or messages.

prevents

Secure development lifecycle can require consistent interface contracts and canonicalization rules that reduce interpretation conflicts between components.

prevents

Explicit application security requirements can mandate unambiguous protocol and data-format specifications that prevent divergent interpretations.

prevents

Secure architecture principles include well-defined component boundaries and shared data models that limit conflicting state perceptions.

prevents

Secure coding standards can enforce canonical input handling and strict protocol compliance to avoid misinterpretation between products.

References