Security Resilience

CVE-2024-20493

Cisco Adaptive Security Appliance Software 9.12.1 … 9.8.4.8

Published
23 October 2024
Modified
11 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0055 45th percentile
Risk Priority 45 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-20493 is a medium-severity Missing Release of Resource after Effective Lifetime (CWE-772) vulnerability in Cisco Adaptive Security Appliance Software. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked at the 45th 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 SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A vulnerability in the login authentication functionality of the Remote Access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to deny further VPN user authentications…

more

for several minutes, resulting in a temporary denial of service (DoS) condition. This vulnerability is due to ineffective handling of memory resources during the authentication process. An attacker could exploit this vulnerability by sending crafted packets, which could cause resource exhaustion of the authentication process. A successful exploit could allow the attacker to deny authentication for Remote Access SSL VPN users for several minutes, resulting in a temporary DoS condition.

CWE(s)
CWE-772

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1003.007 Proc Filesystem Credential Access
Adversaries may gather credentials from the proc filesystem or `/proc`.
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-20481Same product: Cisco Adaptive Security Appliance Software
CVE-2023-20095Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20082Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20341Same product: Cisco Adaptive Security Appliance Software
CVE-2023-20086Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20408Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20494Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20353Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20039Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20349Same product: Cisco Adaptive Security Appliance Software

Affected Assets

cisco
secure firewall threat defense
6.2.3, 6.2.3.1, 6.2.3.10, 6.2.3.11, 6.2.3.12
cisco
adaptive security appliance software
9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing resource releases through dynamic analysis or stress testing.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented development standards and tools can mandate explicit resource-release patterns in code.

SC-6 Resource Availability partial match

Resource-quota allocation limits the blast radius of an unreleased-resource exhaustion condition.

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.

DE.CM-09 partial match
blocks

Runtime monitoring may surface resource-exhaustion symptoms but does not address release logic.

ID.AM-08 partial match
blocks

Lifecycle management explicitly requires handling resources through end-of-life including release.

PR.IR-04 partial match
blocks

Capacity monitoring can detect exhaustion caused by unreleased resources but does not prevent the root defect.

PR.PS-06 partial match
blocks

Secure SDLC practices directly prevent missing resource-release defects during development.

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.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
degrades

Explicit information-deletion requirements directly address timely release of resources after use.

References