The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 3.x and…
Priority LOW 22CWE-17Published · Updated
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- — Not recorded in CVSS 2.0
- Attack complexity
- Medium
- Impact type
- —
- Confidentiality · integrity · availability
- None · Partial · Partial
- Fix status
- Partial Red Hat: 16 fixed, 1 without a fix
Attack profile from CVSS 2.0 · NVD. Fix status from CNA and Red Hat.
Summary
The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 3.x and 4.x before 4.2.8p2 performs state-variable updates upon receiving certain invalid packets, which makes it easier for man-in-the-middle attackers to cause a denial of service (synchronization loss) by spoofing the source IP address of a peer.
Why it matters now
EPSS 0.00902 59th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 16 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:* | up to 4.2.7p444 | Vulnerable | NTP Project |
- cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:* Versions up to 4.2.7p444 Vulnerable ·NTP Project
Remediation
Red Hat 2 advisories
- RHSA-2015:2231 Released 2015-11-19 · Red Hat rating Moderatentp security, bug fix, and enhancement update
- Red Hat Enterprise Linux Client (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux Client Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- Red Hat Enterprise Linux ComputeNode (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux ComputeNode Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- Red Hat Enterprise Linux Server (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux Server Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- Red Hat Enterprise Linux Workstation (v. 7) ntp-4.2.6p5-22.el7, ntpdate-4.2.6p5-22.el7
- Red Hat Enterprise Linux Workstation Optional (v. 7) ntp-doc-4.2.6p5-22.el7, ntp-perl-4.2.6p5-22.el7, sntp-4.2.6p5-22.el7
- RHSA-2015:1459 Released 2015-07-21 · Red Hat rating Moderatentp security, bug fix, and enhancement update
- Red Hat Enterprise Linux Desktop (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux Desktop Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
- Red Hat Enterprise Linux HPC Node (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux HPC Node Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
- Red Hat Enterprise Linux Server (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux Server Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
- Red Hat Enterprise Linux Workstation (v. 6) ntp-4.2.6p5-5.el6, ntpdate-4.2.6p5-5.el6
- Red Hat Enterprise Linux Workstation Optional (v. 6) ntp-doc-4.2.6p5-5.el6, ntp-perl-4.2.6p5-5.el6
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux ComputeNode (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux ComputeNode Optional (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux HPC Node (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2015:2231 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2015:1459 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2015:2231 |
Timeline
- 2026-10-02 Threatist record created from CVE-2015-1799
- 2026-10-03 Alias added: GHSA-q9p8-4cvj-q5fj
References
Advisory 16
- DSA-3222
- 20150408 Network Time Protocol Daemon Symmetric Mode Packet Processing Denial of Service Vulnerability
- USN-2567-1
- VU#374268
- SSRT102029
- FEDORA-2015-5761
- http://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
- FEDORA-2015-5874
- APPLE-SA-2015-06-30-2
- openSUSE-SU-2015:0775
- GLSA-201509-01
- MDVSA-2015:202
- HPSBHF03557
- RHSA-2015:1459
- 20150408 Multiple Vulnerabilities in ntpd (April 2015) Affecting Cisco Products
- DSA-3223
Other 6
- [chrony-announce] 20150407 chrony-1.31.1 released (security)
- https://kc.mcafee.com/corporate/index?page=content&id=SB10114
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- http://www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
- http://support.apple.com/kb/HT204942
- http://bugs.ntp.org/show_bug.cgi?id=2781
More NTP Project Ntp vulnerabilities
- TI-2015-06541 Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows… CVSS 3.1CRITICAL 9.8
- TI-2014-07543 Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers… CVSS 2.0HIGH 7.5
- TI-2013-04524 The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote… CVSS 2.0MEDIUM 5.0
- TI-2016-06333 The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a… CVSS 3.1HIGH 7.5
- TI-2018-08842 Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker… CVSS 3.0CRITICAL 9.8
- TI-2016-04280 ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon… CVSS 3.1HIGH 7.5
Sources
- CVE-2015-1799 · CVE Program
- CVE-2015-1799 · NVD
- FIRST EPSS
- GHSA-q9p8-4cvj-q5fj · GitHub Advisory Database · CC BY 4.0
- CVE-2015-1799 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences