CVE-2024-20382

XSS in Cisco Adaptive Security Appliance Software 9.12.1 … 9.8.4.8

XSS

Published

23 October 2024

Modified

11 August 2026

Patch / advisory

View advisory

CVSS Score v3.1 6.1

Click a component to see what it means

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Score 0.0039 32th percentile

Risk Priority 46 floored blend · peak EPSS

Summary

CVE-2024-20382 is a medium-severity Basic XSS (CWE-80) vulnerability in Cisco Adaptive Security Appliance Software. Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); 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

🇪🇺 ENISA EUVD: EUVD-2024-18097

Vulnerability Data

A vulnerability in the VPN web client services feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a browser that…

is accessing an affected device. This vulnerability is due to improper validation of user-supplied input to application endpoints. An attacker could exploit this vulnerability by persuading a user to follow a link designed to submit malicious input to the affected application. A successful exploit could allow the attacker to execute arbitrary HTML or script code in the browser in the context of the web services page.

CWE(s): CWE-80

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access

Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.

attack.mitre.org →

T1539 Steal Web Session Cookie Credential Access

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.

attack.mitre.org →

T1189 Drive-by Compromise Initial Access

Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.

attack.mitre.org →

Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20070Same product: Cisco Adaptive Security Appliance Software

CVE-2024-20341Same product: Cisco Adaptive Security Appliance Software

CVE-2020-3580Same product: Cisco Adaptive Security Appliance Software

CVE-2026-20102Same product: Cisco Adaptive Security Appliance Software

CVE-2020-3259Same product: Cisco Adaptive Security Appliance Software

CVE-2026-20103Same product: Cisco Adaptive Security Appliance Software

CVE-2024-20299Same product: Cisco Adaptive Security Appliance Software

CVE-2024-20268Same product: Cisco Adaptive Security Appliance Software

CVE-2023-20264Same product: Cisco Adaptive Security Appliance Software

CVE-2024-20384Same product: Cisco Adaptive Security Appliance Software

Affected Assets

cisco

adaptive security appliance software

9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1

cisco

secure firewall threat defense

6.2.3.1, 6.2.3.10, 6.2.3.11, 6.2.3.12, 6.2.3.13

Mitigating Controls

Control response

Prevent

Stop it (NIST 800-53)

—

Detect

Catch it (NIST detect / respond)

—

Harden

Shrink the surface (DISA STIG)

—

Validate

Prove the fix (OWASP ASVS)

V1.2.1
V1.3.1
V1.3.3
V1.3.4

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing or incorrect neutralization of script tags through targeted XSS test cases.

SI-10 Information Input Validation good match

Input validation explicitly requires checking and neutralizing untrusted web inputs containing script-related characters before they reach a downstream renderer.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles include mandatory output encoding and neutralization of HTML metacharacters to stop injection at the source.

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 output encoding and input validation that prevent basic XSS.

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 in development catches unneutralized script tags before release.

A.8.25 Secure development life cycle partial match

prevents

Secure SDLC mandates input validation and output encoding that directly prevent basic XSS.

A.8.26 Application security requirements partial match

prevents

Application security requirements explicitly call for neutralization of script-related HTML tags.

A.8.28 Secure coding partial match

prevents

Secure coding standards require proper escaping of <, >, & to block XSS.