Vulnerability Database

346,508

Total vulnerabilities in the database

CVE-2019-1758 — cisco / ios

Improper Authentication

A vulnerability in 802.1x function of Cisco IOS Software on the Catalyst 6500 Series Switches could allow an unauthenticated, adjacent attacker to access the network prior to authentication. The vulnerability is due to how the 802.1x packets are handled in the process path. An attacker could exploit this vulnerability by attempting to connect to the network on an 802.1x configured port. A successful exploit could allow the attacker to intermittently obtain access to the network.

  • Published: Mar 28, 2019
  • Updated: Nov 9, 2025
  • CVE: CVE-2019-1758
  • Severity: Low
  • Exploit:

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 15.1(2)sy10 15.1(2)sy10.x
cisco / ios 15.2(2)sy 15.2(2)sy.x
cisco / ios 12.2(33)sxj8 12.2(33)sxj8.x
cisco / ios 15.2(1)sy1a 15.2(1)sy1a.x
cisco / ios 15.2(1)sy 15.2(1)sy.x
cisco / ios 15.4(1)sy 15.4(1)sy.x
cisco / ios 15.1(2)sy3 15.1(2)sy3.x
cisco / ios 12.2(33)sxj6 12.2(33)sxj6.x
cisco / ios 15.1(1)sy4 15.1(1)sy4.x
cisco / ios 15.1(2)sy 15.1(2)sy.x
cisco / ios 15.2(1)sy3 15.2(1)sy3.x
cisco / ios 15.1(2)sy1 15.1(2)sy1.x
cisco / ios 15.1(1)sy6 15.1(1)sy6.x
cisco / ios 15.3(3)ja1n 15.3(3)ja1n.x
cisco / ios 15.2(1)sy2 15.2(1)sy2.x
cisco / ios 15.1(2)sy6 15.1(2)sy6.x
cisco / ios 12.2(33)sxj9 12.2(33)sxj9.x
cisco / ios 15.3(1)sy1 15.3(1)sy1.x
cisco / ios 15.3(1)sy2 15.3(1)sy2.x
cisco / ios 15.3(1)sy 15.3(1)sy.x
cisco / ios 15.4(1)sy2 15.4(1)sy2.x
cisco / ios 15.1(2)sy7 15.1(2)sy7.x
cisco / ios 15.1(2)sy8 15.1(2)sy8.x
cisco / ios 15.2(2)sy1 15.2(2)sy1.x
cisco / ios 15.2(1)sy4 15.2(1)sy4.x
cisco / ios 15.4(1)sy1 15.4(1)sy1.x
cisco / ios 15.1(1)sy1 15.1(1)sy1.x
cisco / ios 15.1(1)sy5 15.1(1)sy5.x
cisco / ios 15.1(2)sy11 15.1(2)sy11.x
cisco / ios 12.2(33)sxj10 12.2(33)sxj10.x
cisco / ios 15.1(2)sy4a 15.1(2)sy4a.x
cisco / ios 15.1(2)sy2 15.1(2)sy2.x
cisco / ios 15.2(2)sy2 15.2(2)sy2.x
cisco / ios 15.5(1)sy 15.5(1)sy.x
cisco / ios 15.1(2)sy4 15.1(2)sy4.x
cisco / ios 15.1(2)sy5 15.1(2)sy5.x
cisco / ios 15.2(1)sy1 15.2(1)sy1.x
cisco / ios 15.1(1)sy3 15.1(1)sy3.x
cisco / ios 15.2(1)sy0a 15.2(1)sy0a.x
cisco / ios 15.1(1)sy2 15.1(1)sy2.x
cisco / ios 12.2(33)sxj7 12.2(33)sxj7.x
cisco / ios 15.2(4)jn1 15.2(4)jn1.x
cisco / ios 15.5(1)sy1 15.5(1)sy1.x
cisco / ios 15.1(2)sy9 15.1(2)sy9.x
cisco / ios 15.2(2)sy3 15.2(2)sy3.x
cisco / ios 15.1(3)svo2 15.1(3)svo2.x
cisco / ios 15.4(1)sy3 15.4(1)sy3.x
cisco / ios 15.1(3)svk4c 15.1(3)svk4c.x
cisco / ios 15.3(0)sy 15.3(0)sy.x
cisco / ios 15.2(1)sy5 15.2(1)sy5.x
cisco / ios 15.1(3)svp1 15.1(3)svp1.x
cisco / ios 15.6(2)sp3b 15.6(2)sp3b.x
cisco / ios 15.2(3)ea1 15.2(3)ea1.x
cisco / ios 15.2(4a)ea5 15.2(4a)ea5.x
cisco / ios 15.1(3)svk4b 15.1(3)svk4b.x
cisco / ios 15.1(2)sg8a 15.1(2)sg8a.x
cisco / ios 15.1(4)m12c 15.1(4)m12c.x
cisco / ios 15.1(3)svg3d 15.1(3)svg3d.x
cisco / ios 15.1(3)svn2 15.1(3)svn2.x
cisco / ios 15.1(3)svi1b 15.1(3)svi1b.x
cisco / ios 15.3(3)jf35 15.3(3)jf35.x
cisco / ios 15.1(3)svo1 15.1(3)svo1.x
cisco / ios 15.1(3)svm3 15.1(3)svm3.x
cisco / ios 15.3(3)ji2 15.3(3)ji2.x
cisco / ios 15.2(1)sy7 15.2(1)sy7.x
cisco / ios 15.2(1)sy6 15.2(1)sy6.x
cisco / ios 15.1(3)svp2 15.1(3)svp2.x
cisco / ios 15.1(2)sy13 15.1(2)sy13.x
cisco / ios 15.5(1)sy2 15.5(1)sy2.x
cisco / ios 15.1(2)sy12 15.1(2)sy12.x
cisco / ios 12.2(60)ez12 12.2(60)ez12.x
cisco / ios 15.4(1)sy4 15.4(1)sy4.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.