Auth bypass in NTP
CVE-2016-4953
ntpd in NTP 4.x before 4.2.8p8 allows remote attackers to cause a denial of service (ephemeral-association demobilization) by sending a spoofed crypto-NAK packet with incorrect authentication data at a certain time.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.172 (97.1th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.172 · newest: 0.172 · change: 0.000
Affected products
- NTP — versions 4.2.8
- Oracle Solaris — versions 10, 11.3
- Siemens Simatic Net Cp 443-1 Opc Ua
- Siemens Simatic Net Cp 443-1 Opc Ua Firmware
- Siemens Tim 4r-Ie
- Siemens Tim 4r-Ie Dnp3
- Siemens Tim 4r-Ie Dnp3 Firmware
- Siemens Tim 4r-Ie Firmware
- openSUSE Leap — versions 42.1
- openSUSE — versions 13.2
Weakness classification (CWE)
References
- lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html (vendor-advisory, Mailing List, Third Party Advisory)
- www.securityfocus.com/bid/91010 (VDB Entry, Third Party Advisory, vdb-entry)
- lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html (vendor-advisory, Mailing List, Third Party Advisory)
- security.FreeBSD.org/advisories/FreeBSD-SA-16:24.ntp.asc (vendor-advisory, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html (vendor-advisory)
- h20566.www2.hpe.com/hpsc/doc/public/display (Third Party Advisory)
- support.ntp.org/bin/view/Main/NtpBug3045 (Patch, Vendor Advisory)
- www.securitytracker.com/id/1036037 (VDB Entry, Third Party Advisory, vdb-entry)
- lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html (vendor-advisory, Mailing List, Third Party Advisory)
- www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html (Third Party Advisory)
Frequently asked questions
- What is CVE-2016-4953?
- CVE-2016-4953 is a high-severity vulnerability in NTP, classified under Improper Authentication. CVSS score: 7.5/10. Published 2016-07-05.
- How severe is CVE-2016-4953?
- High severity. CVSS v3 base score is 7.5 out of 10.