Vulnerability Database

383,371

Total vulnerabilities in the database

CVE-2024-20256 — cisco / asyncos

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

A vulnerability in the web-based management interface of Cisco AsyncOS Software for Cisco Secure Email and Web Manager and Secure Web Appliance could allow an authenticated, remote attacker to conduct an XSS attack against a user of the interface.

This vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by persuading a user of an affected interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

  • Published: May 15, 2024
  • Updated: Sep 13, 2026
  • CVE: CVE-2024-20256
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 4.8
  • AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Software Affected versions
cisco / asyncos = 11.7.0-406
cisco / asyncos = 11.7.0-418
cisco / asyncos = 11.7.1-006
cisco / asyncos = 11.7.1-020
cisco / asyncos = 11.7.1-049
cisco / asyncos = 11.7.2-011
cisco / asyncos = 11.8.0-414
cisco / asyncos = 11.8.1-023
cisco / asyncos = 11.8.3-018
cisco / asyncos = 11.8.3-021
cisco / asyncos = 12.0.1-268
cisco / asyncos = 12.0.3-007
cisco / asyncos = 12.5.1-011
cisco / asyncos = 12.5.2-007
cisco / asyncos = 12.5.4-005
cisco / asyncos = 12.5.5-004
cisco / asyncos = 12.5.6-008
cisco / asyncos = 14.0.2-012
cisco / asyncos = 14.0.3-014
cisco / asyncos = 14.0.4-005
cisco / asyncos = 14.5.0-498
cisco / asyncos = 14.5.1-016
cisco / asyncos = 15.0.0-322
cisco / asyncos = 9.0.0-087
cisco / asyncos = 11.0.0-115
cisco / asyncos = 11.0.1-161
cisco / asyncos = 11.5.1-105
cisco / asyncos = 12.0.0-452
cisco / asyncos = 12.0.1-011
cisco / asyncos = 12.5.0-636
cisco / asyncos = 12.5.0-658
cisco / asyncos = 12.5.0-670
cisco / asyncos = 12.5.0-678
cisco / asyncos = 12.8.1-002
cisco / asyncos = 12.8.1-021
cisco / asyncos = 13.0.0-277
cisco / asyncos = 13.6.2-078
cisco / asyncos = 13.8.1-068
cisco / asyncos = 13.8.1-074
cisco / asyncos = 13.8.1-108
cisco / asyncos = 14.0.0-404
cisco / asyncos = 14.1.0-223
cisco / asyncos = 14.1.0-227
cisco / asyncos = 14.2.0-212
cisco / asyncos = 14.2.0-224
cisco / asyncos = 14.2.1-020
cisco / asyncos = 14.3.0-120
cisco / asyncos = 15.0.0-334

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.