Vulnerability Database

393,392

Total vulnerabilities in the database

CVE-2025-20327 — cisco / ios

Improper Validation of Specified Type of Input

A vulnerability in the web UI of Cisco IOS Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to improper input validation. An attacker could exploit this vulnerability by sending a crafted URL in an HTTP request. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

  • Published: Sep 24, 2025
  • Updated: Oct 3, 2026
  • CVE: CVE-2025-20327
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 7.7
  • AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Software Affected versions
cisco / ios = 15.2(6)e2
cisco / ios = 15.2(6)e2a
cisco / ios = 15.2(6)e2b
cisco / ios = 15.2(6)e3
cisco / ios = 15.2(7)e
cisco / ios = 15.2(7)e0a
cisco / ios = 15.2(7)e0b
cisco / ios = 15.2(7)e0s
cisco / ios = 15.2(7)e1
cisco / ios = 15.2(7)e1a
cisco / ios = 15.2(7)e2
cisco / ios = 15.2(7)e2a
cisco / ios = 15.2(7)e3
cisco / ios = 15.2(7)e3k
cisco / ios = 15.2(7)e4
cisco / ios = 15.2(7)e5
cisco / ios = 15.2(7)e6
cisco / ios = 15.2(7)e7
cisco / ios = 15.2(7)e8
cisco / ios = 15.2(7)e9
cisco / ios = 15.2(7)e10
cisco / ios = 15.2(7a)e0b
cisco / ios = 15.2(7b)e0b
cisco / ios = 15.2(8)e
cisco / ios = 15.2(8)e1
cisco / ios = 15.2(8)e2
cisco / ios = 15.2(8)e3
cisco / ios = 15.2(8)e4
cisco / ios = 15.2(8)e5

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.