Vulnerability Database

346,508

Total vulnerabilities in the database

CVE-2018-0163 — cisco / ios

Improper Authentication

A vulnerability in the 802.1x multiple-authentication (multi-auth) feature of Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass the authentication phase on an 802.1x multi-auth port. The vulnerability is due to a logic change error introduced into the code. An attacker could exploit this vulnerability by trying to access an 802.1x multi-auth port after a successful supplicant has authenticated. An exploit could allow the attacker to bypass the 802.1x access controls and obtain access to the network. Cisco Bug IDs: CSCvg69701.

  • Published: Mar 28, 2018
  • Updated: Nov 9, 2025
  • CVE: CVE-2018-0163
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 6.5
  • AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v2:

  • Severity: Low
  • Score: 3.3
  • AV:A/AC:L/Au:N/C:N/I:P/A:N
Software From Fixed in
cisco / ios 15.4(3)m6 15.4(3)m6.x
cisco / ios 15.4(3)m6a 15.4(3)m6a.x
cisco / ios 15.4(3)m7 15.4(3)m7.x
cisco / ios 15.4(3)m7a 15.4(3)m7a.x
cisco / ios 15.4(3)m8 15.4(3)m8.x
cisco / ios 15.4(3.0i)m6 15.4(3.0i)m6.x
cisco / ios 15.5(3)m3 15.5(3)m3.x
cisco / ios 15.5(3)m4 15.5(3)m4.x
cisco / ios 15.5(3)m4a 15.5(3)m4a.x
cisco / ios 15.5(3)m4b 15.5(3)m4b.x
cisco / ios 15.5(3)m4c 15.5(3)m4c.x
cisco / ios 15.5(3)m5 15.5(3)m5.x
cisco / ios 15.5(3)m5a 15.5(3)m5a.x
cisco / ios 15.5(3)m6 15.5(3)m6.x
cisco / ios 15.5(3)m6a 15.5(3)m6a.x
cisco / ios 15.6(1)t2 15.6(1)t2.x
cisco / ios 15.6(1)t3 15.6(1)t3.x
cisco / ios 15.6(2)t1 15.6(2)t1.x
cisco / ios 15.6(2)t2 15.6(2)t2.x
cisco / ios 15.6(2)t3 15.6(2)t3.x
cisco / ios 15.6(3)m 15.6(3)m.x
cisco / ios 15.6(3)m0a 15.6(3)m0a.x
cisco / ios 15.6(3)m1 15.6(3)m1.x
cisco / ios 15.6(3)m1a 15.6(3)m1a.x
cisco / ios 15.6(3)m1b 15.6(3)m1b.x
cisco / ios 15.6(3)m2 15.6(3)m2.x
cisco / ios 15.6(3)m2a 15.6(3)m2a.x
cisco / ios 15.6(3)m3 15.6(3)m3.x
cisco / ios 15.6(3)m3a 15.6(3)m3a.x
cisco / ios 15.7(3)m 15.7(3)m.x
cisco / ios 15.7(3)m0a 15.7(3)m0a.x
cisco / ios 15.7(3)m1 15.7(3)m1.x
cisco / ios 15.7(3)m2 15.7(3)m2.x

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.