MEDIUM
OpenNTPD before 6.0p1 does not validate the CN for HTTPS constraint requests, which allows remote attackers to bypass the man-in-the-middle mitigations via a crafted timestamp constraint with a valid certificate
Published Jan 31, 2017
5.9
MEDIUMCVSS 3.0
EPSS 0.70%
Description
OpenNTPD before 6.0p1 does not validate the CN for HTTPS constraint requests, which allows remote attackers to bypass the man-in-the-middle mitigations via a crafted timestamp constraint with a valid certificate.
Affected products
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
5.9 MEDIUM NVD
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact High
Availability Impact None
4.3 MEDIUM NVD
AV:N/AC:M/Au:N/C:N/I:P/A:N
Access Vector Network
Access Complexity Medium
Authentication None
Confidentiality Impact None
Integrity Impact Partial
Availability Impact None
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
0.70% 0.00702
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.00702
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 (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.70% (0.00702) | 51.51th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.70% (0.00702) | 48.22th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.27% (0.00270) | 48.43th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.17% (0.00169) | 55.22th | v3 (v2023.03.01) |
| Jul 3, 2024 | 0.17% (0.00169) | 54.11th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.17% (0.00169) | 52.10th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.21% (0.01213) | 66.61th | v2 (v2022.01.01) |
| Feb 17, 2023 | 1.21% (0.01213) | 66.22th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.21% (0.01213) | 64.21th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.21% (0.01213) | 40.54th | v2 (v2022.01.01) |
Weaknesses (1)
References (4)
- http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.sbin/ntpd/constraint.c.diff?r1=1.27&r2=1.28 x_refsource_CONFIRMPatch
- http://www.openntpd.org/txt/release-6.0p1.txt x_refsource_CONFIRMVendor Advisory
- http://www.openwall.com/lists/oss-security/2016/05/23/2 mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2016/05/29/6 mailing-listx_refsource_MLISTMailing ListThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.sbin/ntpd/constraint.c.diff?r1=1.27&r2=1.28 | x_refsource_CONFIRMPatch | |
| http://www.openntpd.org/txt/release-6.0p1.txt | x_refsource_CONFIRMVendor Advisory | |
| http://www.openwall.com/lists/oss-security/2016/05/23/2 | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| http://www.openwall.com/lists/oss-security/2016/05/29/6 | mailing-listx_refsource_MLISTMailing ListThird Party Advisory |
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mitre
Published Jan 31, 2017
Updated Aug 6, 2024
Reserved May 29, 2016
Link CVE-2016-5117
CISA Vulnrichment
Updated n/a