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Fencer Vulns
high 7.8

CVE-2017-17806 json

The HMAC implementation (crypto/hmac.c) in the Linux kernel before 4.14.8 does not validate that the underlying cryptographic hash algorith…

published 2017-12-20 8 y ago modified 2026-06-17 4 mo ago also EUVD-2017-8957

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

The HMAC implementation (crypto/hmac.c) in the Linux kernel before 4.14.8 does not validate that the underlying cryptographic hash algorithm is unkeyed, allowing a local attacker able to use the AF_ALG-based hash interface (CONFIG_CRYPTO_USER_API_HASH) and the SHA-3 hash algorithm (CONFIG_CRYPTO_SHA3) to cause a kernel stack buffer overflow by executing a crafted sequence of system calls that encounter a missing SHA-3 initialization.

Patch / fix

  • linux linux_kernel 3.2.97, 3.16.52, 3.18.89, 4.1.49, 4.4.107, 4.9.71, 4.14.8
  • linux Debian 14, Debian 13, Debian 12 4.14.7-1

debian advisories DEBIAN-CVE-2017-17806

  • linux Ubuntu 14.04 LTS 3.13.0-142.191
  • linux Ubuntu 16.04 LTS 4.4.0-119.143
  • linux-aws Ubuntu 14.04 LTS 4.4.0-1016.16
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1054.63
  • linux-gcp Ubuntu 16.04 LTS 4.13.0-1012.16
  • linux-hwe Ubuntu 16.04 LTS 4.13.0-41.46~16.04.1
  • linux-kvm Ubuntu 16.04 LTS 4.4.0-1020.25
  • linux-oem Ubuntu 16.04 LTS 4.13.0-1022.24

ubuntu advisories UBUNTU-CVE-2017-17806

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-alt RHEL 7 4.14.0-115.el7a
  • perf RHEL 7 4.14.0-115.el7a
  • kernel RHEL 7 4.14.0-115.el7a
  • python-perf RHEL 7 4.14.0-115.el7a
  • kernel-tools RHEL 7 4.14.0-115.el7a
  • kernel-tools-libs RHEL 7 4.14.0-115.el7a
  • kernel-bootwrapper RHEL 7 4.14.0-115.el7a
  • kernel-abi-whitelists RHEL 7 4.14.0-115.el7a

red hat advisories RHSA-2018:2948

  • kernel-ec2 SLE Module for Public Cloud 12 3.12.74-60.64.82.1
  • kernel-xen SLES for SAP 12 SP1, SLES 12 SP1-LTSS, OpenStack Cloud 6 3.12.74-60.64.82.1
  • kernel-syms SLES for SAP 12 SP1, SLES 12 SP1-LTSS, OpenStack Cloud 6 3.12.74-60.64.82.1
  • kernel-source SLES for SAP 12 SP1, SLES 12 SP1-LTSS, OpenStack Cloud 6 3.12.74-60.64.82.1
  • kernel-default SLES for SAP 12 SP1, SLES 12 SP1-LTSS, OpenStack Cloud 6 3.12.74-60.64.82.1
  • kgraft-patch-SLE12-SP1_Update_25 SLES for SAP 12 SP1, SLES 12 SP1-LTSS, OpenStack Cloud 6 1-2.9.1
  • kernel-ec2 SLE Module for Public Cloud 12 3.12.61-52.119.1
  • kernel-rt SLE Real Time 12 SP2 4.4.104-24.1

suse advisories SUSE-SU-2018:0525-1SUSE-SU-2018:0437-1SUSE-SU-2018:0213-1SUSE-SU-2018:0180-1SUSE-SU-2018:0040-1SUSE-SU-2018:0011-1

  • linux Arch Linux 4.14.11-1
  • linux-lts Arch Linux 4.9.74-1
  • linux-zen Arch Linux 4.14.11-1
  • linux-hardened Arch Linux 4.14.11.a-1

arch linux advisories AVG-552AVG-561AVG-571AVG-574

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-2017-17806 updated cvss 5.5

kernel: HMAC implementation does not validate that the underlying cryptographic hash algorithm is unkeyed allowing local attackers to cause denial-of-service

  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) perf 4.14.0-115.el7a, kernel 4.14.0-115.el7a, kernel-alt 4.14.0-115.el7a, python-perf 4.14.0-115.el7a, kernel-tools 4.14.0-115.el7a, kernel-tools-libs 4.14.0-115.el7a, +3 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) kernel-debuginfo-common-ppc64le 4.14.0-115.el7a
    fixed: vendor fix RHSA-2018:2948
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-core, kernel-tools, python3-perf, +17 more Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    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

0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
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.