Vulnerability Database

328,409

Total vulnerabilities in the database

CVE-2019-11479

Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.

  • Published: Jun 19, 2019
  • Updated: Nov 9, 2025
  • CVE: CVE-2019-11479
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2:

  • Severity: Medium
  • Score: 5
  • AV:N/AC:L/Au:N/C:N/I:N/A:P
Software From Fixed in
linux / linux_kernel 4.4 4.4.182
linux / linux_kernel 4.9 4.9.182
linux / linux_kernel 4.14 4.14.127
linux / linux_kernel 4.19 4.19.52
linux / linux_kernel 5.1 5.1.11
f5 / big-ip_advanced_firewall_manager 14.0.0 14.0.1.1
f5 / big-ip_advanced_firewall_manager 13.1.0 13.1.3.2
f5 / big-ip_advanced_firewall_manager 15.0.0 15.0.1.1
f5 / big-ip_advanced_firewall_manager 11.5.2 11.6.5.1
f5 / big-ip_advanced_firewall_manager 12.1.0 12.1.5.1
f5 / big-ip_advanced_firewall_manager 14.1.2 14.1.2.1
f5 / big-ip_access_policy_manager 14.0.0 14.0.1.1
f5 / big-ip_access_policy_manager 13.1.0 13.1.3.2
f5 / big-ip_access_policy_manager 15.0.0 15.0.1.1
f5 / big-ip_access_policy_manager 11.5.2 11.6.5.1
f5 / big-ip_access_policy_manager 12.1.0 12.1.5.1
f5 / big-ip_access_policy_manager 14.1.2 14.1.2.1
f5 / big-ip_application_acceleration_manager 14.0.0 14.0.1.1
f5 / big-ip_application_acceleration_manager 13.1.0 13.1.3.2
f5 / big-ip_application_acceleration_manager 15.0.0 15.0.1.1
f5 / big-ip_application_acceleration_manager 11.5.2 11.6.5.1
f5 / big-ip_application_acceleration_manager 12.1.0 12.1.5.1
f5 / big-ip_application_acceleration_manager 14.1.2 14.1.2.1
f5 / big-ip_link_controller 14.0.0 14.0.1.1
f5 / big-ip_link_controller 13.1.0 13.1.3.2
f5 / big-ip_link_controller 15.0.0 15.0.1.1
f5 / big-ip_link_controller 11.5.2 11.6.5.1
f5 / big-ip_link_controller 12.1.0 12.1.5.1
f5 / big-ip_link_controller 14.1.2 14.1.2.1
f5 / big-ip_policy_enforcement_manager 14.0.0 14.0.1.1
f5 / big-ip_policy_enforcement_manager 13.1.0 13.1.3.2
f5 / big-ip_policy_enforcement_manager 15.0.0 15.0.1.1
f5 / big-ip_policy_enforcement_manager 11.5.2 11.6.5.1
f5 / big-ip_policy_enforcement_manager 12.1.0 12.1.5.1
f5 / big-ip_policy_enforcement_manager 14.1.2 14.1.2.1
f5 / big-ip_webaccelerator 14.0.0 14.0.1.1
f5 / big-ip_webaccelerator 13.1.0 13.1.3.2
f5 / big-ip_webaccelerator 15.0.0 15.0.1.1
f5 / big-ip_webaccelerator 11.5.2 11.6.5.1
f5 / big-ip_webaccelerator 12.1.0 12.1.5.1
f5 / big-ip_webaccelerator 14.1.2 14.1.2.1
f5 / big-ip_application_security_manager 14.0.0 14.0.1.1
f5 / big-ip_application_security_manager 13.1.0 13.1.3.2
f5 / big-ip_application_security_manager 15.0.0 15.0.1.1
f5 / big-ip_application_security_manager 11.5.2 11.6.5.1
f5 / big-ip_application_security_manager 12.1.0 12.1.5.1
f5 / big-ip_application_security_manager 14.1.2 14.1.2.1
f5 / big-ip_local_traffic_manager 14.0.0 14.0.1.1
f5 / big-ip_local_traffic_manager 13.1.0 13.1.3.2
f5 / big-ip_local_traffic_manager 15.0.0 15.0.1.1
f5 / big-ip_local_traffic_manager 11.5.2 11.6.5.1
f5 / big-ip_local_traffic_manager 12.1.0 12.1.5.1
f5 / big-ip_local_traffic_manager 14.1.2 14.1.2.1
f5 / big-ip_fraud_protection_service 14.0.0 14.0.1.1
f5 / big-ip_fraud_protection_service 13.1.0 13.1.3.2
f5 / big-ip_fraud_protection_service 15.0.0 15.0.1.1
f5 / big-ip_fraud_protection_service 11.5.2 11.6.5.1
f5 / big-ip_fraud_protection_service 12.1.0 12.1.5.1
f5 / big-ip_fraud_protection_service 14.1.2 14.1.2.1
f5 / big-ip_global_traffic_manager 14.0.0 14.0.1.1
f5 / big-ip_global_traffic_manager 13.1.0 13.1.3.2
f5 / big-ip_global_traffic_manager 15.0.0 15.0.1.1
f5 / big-ip_global_traffic_manager 11.5.2 11.6.5.1
f5 / big-ip_global_traffic_manager 12.1.0 12.1.5.1
f5 / big-ip_global_traffic_manager 14.1.2 14.1.2.1
f5 / big-ip_analytics 14.0.0 14.0.1.1
f5 / big-ip_analytics 13.1.0 13.1.3.2
f5 / big-ip_analytics 15.0.0 15.0.1.1
f5 / big-ip_analytics 11.5.2 11.6.5.1
f5 / big-ip_analytics 12.1.0 12.1.5.1
f5 / big-ip_analytics 14.1.2 14.1.2.1
f5 / big-ip_edge_gateway 14.0.0 14.0.1.1
f5 / big-ip_edge_gateway 13.1.0 13.1.3.2
f5 / big-ip_edge_gateway 15.0.0 15.0.1.1
f5 / big-ip_edge_gateway 11.5.2 11.6.5.1
f5 / big-ip_edge_gateway 12.1.0 12.1.5.1
f5 / big-ip_edge_gateway 14.1.2 14.1.2.1
f5 / big-ip_domain_name_system 14.0.0 14.0.1.1
f5 / big-ip_domain_name_system 13.1.0 13.1.3.2
f5 / big-ip_domain_name_system 15.0.0 15.0.1.1
f5 / big-ip_domain_name_system 11.5.2 11.6.5.1
f5 / big-ip_domain_name_system 12.1.0 12.1.5.1
f5 / big-ip_domain_name_system 14.1.2 14.1.2.1
canonical / ubuntu_linux 16.04 16.04.x
canonical / ubuntu_linux 18.04 18.04.x
canonical / ubuntu_linux 18.10 18.10.x
canonical / ubuntu_linux 19.04 19.04.x
canonical / ubuntu_linux 14.04 14.04.x
redhat / enterprise_linux 7.0 7.0.x
f5 / enterprise_manager 3.1.1 3.1.1.x
f5 / big-iq_centralized_management 5.1.0 5.4.0.x
f5 / big-iq_centralized_management 6.0.0 6.1.0.x
f5 / iworkflow 2.3.0 2.3.0.x
redhat / virtualization_host 4.0 4.0.x
f5 / traffix_signaling_delivery_controller 5.0.0 5.1.0.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.