CVE-2016-5117

low-risk
Published 2017-01-31

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.

Do I need to act?

-
0.27% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.9/10 Medium
NETWORK / HIGH complexity

Affected Products (1)

Openntpd

Affected Vendors

Openntpd

References (8)

Patch http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.sbin/ntpd/constraint.c.diff?r1=...
Vendor Advisory http://www.openntpd.org/txt/release-6.0p1.txt
Mailing List http://www.openwall.com/lists/oss-security/2016/05/23/2
Mailing List http://www.openwall.com/lists/oss-security/2016/05/29/6
Patch http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.sbin/ntpd/constraint.c.diff?r1=...
Vendor Advisory http://www.openntpd.org/txt/release-6.0p1.txt
Mailing List http://www.openwall.com/lists/oss-security/2016/05/23/2
Mailing List http://www.openwall.com/lists/oss-security/2016/05/29/6
24
/ 100
low-risk
Severity 18/34 · Moderate
Exploitability 1/34 · Minimal
Exposure 5/34 · Minimal