What’s Vulnerable › Vulnerabilities

CVE-2019-18805

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-11-07 · updated 2026-06-17
• Weakness: CWE-190

Description

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.

Affected products

• Brocade Fabric OS: all versions
• Linux kernel: from 4.4 before 4.4.180; from 4.9 before 4.9.172; from 4.14 before 4.14.115; from 4.19 before 4.19.38; from 5.0 before 5.0.11; 5.1-rc1, 5.1-rc2, 5.1-rc3, 5.1-rc4, 5.1-rc5, 5.1-rc6 (+1) — fixed in 4.14.115, 4.19.38, 4.4.180, 4.9.172, 5.0.11
• Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
• NetApp Aff A400 Firmware: all versions
• NetApp Aff A700S Firmware: all versions
• NetApp Data Availability Services: all versions
• E-Series SANtricity OS Controller Software 11.x: from 11.0.0 through 11.60.3
• NetApp Fas8300 Firmware: all versions
• NetApp Fas8700 Firmware: all versions
• NetApp H610S Firmware: all versions
• NetApp Hci Compute Node: all versions
• NetApp Hci Management Node: all versions
• NetApp Hci Storage Node: all versions
• NetApp Solidfire: all versions
• NetApp Steelstore Cloud Integrated Storage: all versions
• openSUSE Leap: 15.0, 15.1
• Red Hat Enterprise Linux: 7.0

How to fix

Upgrade to a fixed version: Linux kernel 4.14.115, 4.19.38, 4.4.180, 4.9.172. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00035.html
• http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00039.html
• https://access.redhat.com/errata/RHSA-2020:0740
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.11
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19fad20d15a6494f47f85d869f00b11343ee5c78
• https://security.netapp.com/advisory/ntap-20191205-0001/
• http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00035.html
• http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00039.html
• https://access.redhat.com/errata/RHSA-2020:0740
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.11
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19fad20d15a6494f47f85d869f00b11343ee5c78
• https://security.netapp.com/advisory/ntap-20191205-0001/

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