openssh: Out of sequence NEWKEYS message can allow remote attacker to cause denial of service
Published Jan 21, 2018
7.5
HIGHCVSS 3.1
EPSS 15.72%
Description
sshd in OpenSSH before 7.4 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an out-of-sequence NEWKEYS message, as demonstrated by Honggfuzz, related to kex.c and packet.c.
Affected products
No data.
Configuration 2
- 7.0
- 8.0
Configuration 3
- 14.04
- 16.04
- 18.04
Configuration 4
- n/a
- n/a
- n/a
- ≥ 9.4
- n/a
- n/a
- n/a
- n/a
Configuration 5
- n/a
Running on/with
- n/a
No data.
Red Hat Enterprise Linux 7
openssh-0:7.4p1-11.el7
Fixed · RHSA-2017:2029
Red Hat Enterprise Linux 5
openssh
Will not fix
Red Hat Enterprise Linux 6
openssh
Will not fix
Red Hat Enterprise Linux 8
openssh
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | openssh-0:7.4p1-11.el7 | Fixed | RHSA-2017:2029 |
| Red Hat Enterprise Linux 5 | openssh | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | openssh | Will not fix | n/a |
| Red Hat Enterprise Linux 8 | openssh | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue affects the versions of openssh as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7 (versions 7.3 and earlier). For Red Hat Enterprise Linux 7 (versions 7.4 and later), this issue was fixed by the Security Advisory RHSA-2017:2029. For Red Hat Enterprise Linux 6, Red Hat Product Security has rated this issue as having Low security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
AV:N/AC:L/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Apr 28, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (30 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 15.72% (0.15716) | 96.76th | v5 (v2026.06.15) |
| Jun 15, 2026 | 16.00% (0.16002) | 96.48th | v5 (v2026.06.15) |
| Feb 4, 2026 | 3.75% (0.03751) | 87.73th | v4 (v2025.03.14) |
| Feb 1, 2026 | 4.97% (0.04970) | 89.46th | v4 (v2025.03.14) |
| Jan 4, 2026 | 3.75% (0.03751) | 87.67th | v4 (v2025.03.14) |
| Jan 1, 2026 | 4.97% (0.04970) | 89.41th | v4 (v2025.03.14) |
| Dec 4, 2025 | 3.75% (0.03751) | 87.60th | v4 (v2025.03.14) |
| Dec 1, 2025 | 4.97% (0.04970) | 89.32th | v4 (v2025.03.14) |
| Nov 4, 2025 | 3.75% (0.03751) | 87.52th | v4 (v2025.03.14) |
| Nov 1, 2025 | 4.97% (0.04970) | 89.23th | v4 (v2025.03.14) |
| Oct 4, 2025 | 3.12% (0.03120) | 86.33th | v4 (v2025.03.14) |
| Oct 2, 2025 | 4.79% (0.04793) | 89.06th | v4 (v2025.03.14) |
| Oct 1, 2025 | 3.62% (0.03622) | 87.38th | v4 (v2025.03.14) |
| Sep 30, 2025 | 2.22% (0.02223) | 83.93th | v4 (v2025.03.14) |
| Jul 30, 2025 | 1.19% (0.01193) | 78.00th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.24% (0.02242) | 83.07th | v4 (v2025.03.14) |
| Mar 29, 2025 | 4.49% (0.04487) | 81.48th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.60% (0.02601) | 84.59th | v4 (v2025.03.14) |
| Feb 2, 2025 | 10.89% (0.10891) | 95.13th | v3 (v2023.03.01) |
| Dec 17, 2024 | 12.11% (0.12112) | 95.35th | v3 (v2023.03.01) |
| Dec 12, 2024 | 5.81% (0.05810) | 93.66th | v3 (v2023.03.01) |
| Mar 18, 2024 | 5.23% (0.05228) | 92.83th | v3 (v2023.03.01) |
| Aug 17, 2023 | 4.68% (0.04682) | 91.58th | v3 (v2023.03.01) |
| Jul 24, 2023 | 5.87% (0.05874) | 92.40th | v3 (v2023.03.01) |
| Jun 14, 2023 | 4.23% (0.04233) | 91.03th | v3 (v2023.03.01) |
| May 8, 2023 | 4.92% (0.04919) | 91.54th | v3 (v2023.03.01) |
| Mar 7, 2023 | 3.28% (0.03281) | 89.76th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.17% (0.02172) | 80.77th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.17% (0.02172) | 78.91th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.17% (0.02172) | 57.73th | v2 (v2022.01.01) |
References (15)
- http://blog.swiecki.net/2018/01/fuzzing-tcp-servers.html x_refsource_MISCPatchThird Party Advisory
- http://www.securityfocus.com/bid/102780 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2016-10708 Vendor Advisory
- https://anongit.mindrot.org/openssh.git/commit/?id=28652bca29046f62c7045e933e6b931de1d16737 x_refsource_MISCPatchThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1537929 Issue Tracking
- https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf x_refsource_CONFIRM
- https://kc.mcafee.com/corporate/index?page=content&id=SB10284 x_refsource_CONFIRM
- https://lists.debian.org/debian-lts-announce/2018/01/msg00031.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2016-10708
- https://security.netapp.com/advisory/ntap-20180423-0003/ x_refsource_CONFIRMThird Party Advisory
- https://support.f5.com/csp/article/K32485746?utm_source=f5support&%3Butm_medium=RSS x_refsource_CONFIRM
- https://usn.ubuntu.com/3809-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2016-10708
- https://www.openssh.com/releasenotes.html x_refsource_MISCRelease NotesVendor Advisory
Change history (0)
No recorded changes yet.