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Fencer Vulns
medium 6.5

CVE-2019-10638 json

In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less pro…

published 2019-07-05 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-2442

cvss
6.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.6%
EPSS 2.6% chance of exploitation in 30 days, percentile 85%
public exploits
0
none known

Summary

In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). An attack may be conducted by hosting a crafted web page that uses WebRTC or gQUIC to force UDP traffic to attacker-controlled IP addresses.

Patch / fix

  • linux linux_kernel 5.1.7
  • linux Debian 14, Debian 13, Debian 12 5.2.6-1

debian advisories DEBIAN-CVE-2019-10638

  • linux Ubuntu 16.04 LTS 4.4.0-161.189
  • linux Ubuntu 18.04 LTS 4.15.0-60.67
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1092.103
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1047.49
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1041.43
  • linux-gcp Ubuntu 18.04 LTS 4.15.0-1042.45
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-60.67~16.04.1
  • linux-hwe Ubuntu 18.04 LTS 5.0.0-27.28~18.04.1

ubuntu advisories UBUNTU-CVE-2019-10638

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 7 3.10.0-1127.el7
  • perf RHEL 7 3.10.0-1127.el7
  • bpftool RHEL 7 3.10.0-1127.el7
  • python-perf RHEL 7 3.10.0-1127.el7
  • kernel-kdump RHEL 7 3.10.0-1127.el7
  • kernel-tools RHEL 7 3.10.0-1127.el7
  • kernel-tools-libs RHEL 7 3.10.0-1127.el7
  • kernel-bootwrapper RHEL 7 3.10.0-1127.el7

red hat advisories RHSA-2020:1016RHSA-2019:3517RHSA-2020:1070RHSA-2019:3309

  • kernel-rt SLE Real Time 12 SP4 4.12.14-8.3.1
  • kernel-syms-rt SLE Real Time 12 SP4 4.12.14-8.3.1
  • kernel-rt_debug SLE Real Time 12 SP4 4.12.14-8.3.1
  • kernel-source-rt SLE Real Time 12 SP4 4.12.14-8.3.1
  • kernel-source-rt Real Time Module 15 SP1 4.12.14-14.8.1
  • kernel-rt Real Time Module 15 SP1 4.12.14-14.8.1
  • kernel-syms-rt Real Time Module 15 SP1 4.12.14-14.8.1
  • kernel-rt_debug Real Time Module 15 SP1 4.12.14-14.8.1

suse advisories SUSE-SU-2019:2450-1SUSE-SU-2019:2430-1SUSE-SU-2019:2069-1SUSE-SU-2019:1855-1SUSE-SU-2019:1854-1SUSE-SU-2019:1852-1

  • kernel-syms openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-obs-qa openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-source openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-default openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-vanilla openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-kvmsmall openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-obs-build openSUSE Leap 15.1 4.12.14-lp151.28.10.1
  • kernel-syms openSUSE Leap 15.0 4.12.14-lp150.12.67.1

opensuse advisories openSUSE-SU-2019:1757-1openSUSE-SU-2019:1716-1

  • hyperv-daemons Azure Linux 3.0 6.6.35.1-1

azure linux advisories AZL-41613

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-10638 updated cvss 3.7

Kernel: net: weak IP ID generation leads to remote device tracking

  • Red Hat Enterprise Linux 7 perf, kernel, kernel-alt, python-perf, kernel-kdump, kernel-tools, +3 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    affected: no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-147.el8, kernel-debuginfo-common-aarch64 4.18.0-147.el8, kernel-debuginfo-common-ppc64le 4.18.0-147.el8 Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-147.el8, kernel 4.18.0-147.el8, bpftool 4.18.0-147.el8, kernel-core 4.18.0-147.el8, kernel-tools 4.18.0-147.el8, python3-perf 4.18.0-147.el8, +15 more
    fixed: vendor fix RHSA-2019:3517
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1127.el7, kernel 3.10.0-1127.el7, bpftool 3.10.0-1127.el7, python-perf 3.10.0-1127.el7, kernel-tools 3.10.0-1127.el7, kernel-tools-libs 3.10.0-1127.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1127.el7 Red Hat Enterprise Linux ComputeNode (v. 7) perf 3.10.0-1127.el7, kernel 3.10.0-1127.el7, bpftool 3.10.0-1127.el7, python-perf 3.10.0-1127.el7, kernel-tools 3.10.0-1127.el7, kernel-tools-libs 3.10.0-1127.el7, +2 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1127.el7
    fixed: vendor fix RHSA-2020:1016
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1127.rt56.1093.el7, kernel-rt-trace 3.10.0-1127.rt56.1093.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1127.rt56.1093.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1127.rt56.1093.el7, kernel-rt-kvm 3.10.0-1127.rt56.1093.el7, kernel-rt-trace 3.10.0-1127.rt56.1093.el7, kernel-rt-debug-kvm 3.10.0-1127.rt56.1093.el7, kernel-rt-trace-kvm 3.10.0-1127.rt56.1093.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1127.rt56.1093.el7
    fixed: vendor fix RHSA-2020:1070
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-147.rt24.93.el8, kernel-rt-core 4.18.0-147.rt24.93.el8, kernel-rt-modules 4.18.0-147.rt24.93.el8, kernel-rt-debug-core 4.18.0-147.rt24.93.el8, kernel-rt-debug-modules 4.18.0-147.rt24.93.el8, kernel-rt-modules-extra 4.18.0-147.rt24.93.el8, +2 more Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-147.rt24.93.el8, kernel-rt-kvm 4.18.0-147.rt24.93.el8, kernel-rt-core 4.18.0-147.rt24.93.el8, kernel-rt-modules 4.18.0-147.rt24.93.el8, kernel-rt-debug-kvm 4.18.0-147.rt24.93.el8, kernel-rt-debug-core 4.18.0-147.rt24.93.el8, +4 more
    fixed: vendor fix RHSA-2019:3309
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1127.el7, kernel 3.10.0-1127.el7, bpftool 3.10.0-1127.el7, python-perf 3.10.0-1127.el7, kernel-kdump 3.10.0-1127.el7, kernel-tools 3.10.0-1127.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1127.el7, kernel-debuginfo-common-x86_64 3.10.0-1127.el7, kernel-debuginfo-common-ppc64le 3.10.0-1127.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1127.el7, kernel 3.10.0-1127.el7, bpftool 3.10.0-1127.el7, python-perf 3.10.0-1127.el7, kernel-tools 3.10.0-1127.el7, kernel-tools-libs 3.10.0-1127.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1127.el7
    fixed: vendor fix RHSA-2020:1016
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.57% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 6.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-326 Inadequate Encryption Strength
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.