Vulnerability Snapshot
CVE-2019-18805 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.
Affected technology: linux_kernel, leap, enterprise_linux, active_iq_unified_manager, data_availability_services, plus 5 other product variants.
Executive Summary
An issue was discovered in net/ipv4/sysctl_net_ipv4.c in the Linux kernel before 5.0.11. There is a net/ipv4/tcp_input.c signed integer overflow in tcp_ack_update_rtt() when userspace writes a very large integer to /proc/sys/net/ipv4/tcp_min_rtt_wlen, leading to a denial of service or possibly unspecified other impact, aka CID-19fad20d15a6.
Why It Matters
CVE-2019-18805 is rated CRITICAL severity, requiring immediate attention from security teams.
CVSS Base Score: 9.8/10
Affected Technologies
Vendors: linux, opensuse, redhat, netapp, broadcom
Products: linux_kernel, leap, enterprise_linux, active_iq_unified_manager, data_availability_services, e-series_santricity_os_controller, hci_management_node, solidfire, steelstore_cloud_integrated_storage, hci_compute_node, hci_storage_node, fabric_operating_system, aff_a700s_firmware, aff_a700s, fas8300_firmware, fas8300, fas8700_firmware, fas8700, aff_a400_firmware, aff_a400, h610s_firmware, h610s
🛡️What Defenders Should Check
Use Vulnios to continuously monitor your exposure to CVE-2019-18805 and similar vulnerabilities.
References & Sources
How Vulnios Detects This
Vulnios scans for this vulnerability using Trivy and Grype for CVE matching against your container images and OS package manifests. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.
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Affected Products
Sources
Related Threat Alerts
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- Critical Vulnerability: CVE-2019-14895 — linux, debian — linux_kernel, debian_linux
- Critical Vulnerability: CVE-2019-18814 — linux — linux_kernel
- Critical Vulnerability: CVE-2019-17133 — linux, debian — linux_kernel, debian_linux
Frequently Asked Questions
What is CVE-2019-18805?
CVE-2019-18805 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. An issue was discovered in net/ipv4/sysctl_net_ipv4.c in the Linux kernel before 5.0.11. There is a net/ipv4/tcp_input.c signed integer overflow in tcp_ack_update_rtt() when userspace writes a very la
Am I affected?
Check whether your environment runs linux_kernel, leap, enterprise_linux, active_iq_unified_manager, data_availability_services. If you operate any of those, treat yourself as in scope until you have evidence otherwise. A Vulnios scan will identify the exact assets carrying the affected version.
How urgent is the response?
Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.
How do I remediate?
Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.
Where can I track exploitation activity?
Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2019-18805. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.
How does Vulnios help with this?
Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.
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