kernel: HMAC implementation does not validate that the underlying cryptographic hash algorithm is unkeyed allowing local attackers to cause denial-of-service
Published Dec 20, 2017
7.8
HIGHCVSS 3.1
EPSS 0.56%
Description
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.
Affected products
No data.
Configuration 1
- < 3.2.97
- ≥ 3.3 · < 3.16.52
- ≥ 3.17 · < 3.18.89
- ≥ 3.19 · < 4.1.49
- ≥ 4.2 · < 4.4.107
- ≥ 4.5 · < 4.9.71
- ≥ 4.10 · < 4.14.8
Configuration 2
- 8.0
- 9.0
- 42.2
- 42.3
- 12
- 12
- 11
- 11
- 12
- 12
- 12
Configuration 3
- 12.04
- 14.04
- 16.04
- 17.10
No data.
Red Hat Enterprise Linux 7
kernel-alt-0:4.14.0-115.el7a
Fixed · RHSA-2018:2948
Red Hat Enterprise Linux 5
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise MRG 2
realtime-kernel
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | kernel-alt-0:4.14.0-115.el7a | Fixed | RHSA-2018:2948 |
| Red Hat Enterprise Linux 5 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise MRG 2 | realtime-kernel | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, and 7, its real-time kernel and Red Hat Enterprise MRG 2. This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE. Future Linux kernel updates for the respective releases may address this issue.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
AV:L/AC:L/Au:N/C:C/I:C/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (14 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.56% (0.00561) | 44.65th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.56% (0.00557) | 41.79th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.04% (0.00042) | 9.92th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.04% (0.00044) | 11.92th | v3 (v2023.03.01) |
| Jul 10, 2024 | 0.04% (0.00044) | 10.38th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00044) | 8.31th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.55% (0.01547) | 74.98th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.55% (0.01547) | 74.94th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.55% (0.01547) | 72.92th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.55% (0.01547) | 51.82th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.42% (0.02421) | 53.88th | v1 |
| Jan 6, 2022 | 2.42% (0.02421) | 53.43th | v1 |
| Sep 1, 2021 | 2.42% (0.02421) | 78.37th | v1 |
| Apr 14, 2021 | 2.42% (0.02421) | 0.00th | v1 |
References (25)
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=af3ff8045bbf3e32f1a448542e73abb4c8ceb6f1 x_refsource_CONFIRMPatch
- http://lists.opensuse.org/opensuse-security-announce/2018-01/msg00006.html vendor-advisoryx_refsource_SUSEIssue TrackingPatchThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2018-01/msg00007.html vendor-advisoryx_refsource_SUSEIssue TrackingPatchThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2018-01/msg00008.html vendor-advisoryx_refsource_SUSEIssue TrackingPatchThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2018-01/msg00014.html vendor-advisoryx_refsource_SUSEIssue TrackingPatchThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2018-01/msg00016.html vendor-advisoryx_refsource_SUSEIssue TrackingThird Party Advisory
- http://www.securityfocus.com/bid/102293 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/errata/RHSA-2018:2948 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2017-17806 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1528323 Issue Tracking
- https://github.com/torvalds/linux/commit/af3ff8045bbf3e32f1a448542e73abb4c8ceb6f1 x_refsource_CONFIRMPatch
- https://lists.debian.org/debian-lts-announce/2018/01/msg00004.html mailing-listx_refsource_MLISTThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2017-17806
- https://usn.ubuntu.com/3583-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3583-2/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3617-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3617-2/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3617-3/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3619-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3619-2/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3632-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2017-17806
- https://www.debian.org/security/2017/dsa-4073 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.debian.org/security/2018/dsa-4082 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.8 x_refsource_CONFIRMIssue TrackingRelease Notes
Change history (0)
No recorded changes yet.