Vulnerability Database

383,371

Total vulnerabilities in the database

CVE-2022-20697 — cisco / ios

Missing Release of Resource after Effective Lifetime

A vulnerability in the web services interface of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper resource management in the HTTP server code. An attacker could exploit this vulnerability by sending a large number of HTTP requests to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

  • Published: Apr 15, 2022
  • Updated: Sep 13, 2026
  • CVE: CVE-2022-20697
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 8.6
  • AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS v2:

  • Severity: Medium
  • Score: 6.8
  • AV:N/AC:L/Au:S/C:N/I:N/A:C
Software Affected versions
cisco / ios = 15.1(3)svr1
cisco / ios = 15.1(3)svr2
cisco / ios = 15.1(3)svr3
cisco / ios = 15.1(3)svs
cisco / ios = 15.1(3)svs1
cisco / ios = 15.1(3)svt1
cisco / ios = 15.1(3)svt2
cisco / ios = 15.1(3)svt3
cisco / ios = 15.1(3)svu1
cisco / ios = 15.1(3)svu2
cisco / ios = 15.1(3)svu10
cisco / ios = 15.1(3)svv1
cisco / ios = 15.2(7)e3
cisco / ios = 15.2(7)e3a
cisco / ios = 15.2(7)e3k
cisco / ios = 15.2(7)e4
cisco / ios = 15.2(8)e
cisco / ios = 15.2(234k)e
cisco / ios = 15.3(3)jk100
cisco / ios = 15.3(3)jpj8
cisco / ios = 15.9(3)m2
cisco / ios = 15.9(3)m2a
cisco / ios = 15.9(3)m3
cisco / ios = 15.9(3)m3a
cisco / ios = 15.9(3)m3b
cisco / ios = 15.9(3)m4
cisco / ios_xe = 3.11.3ae
cisco / ios_xe = 3.11.3e
cisco / ios_xe = 3.11.4e

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.