Description
ntp_crypto.c in ntpd in NTP 4.x before 4.2.8p1, when Autokey Authentication is enabled, allows remote attackers to obtain sensitive information from process memory or cause a denial of service (daemon crash) via a packet containing an extension field with an invalid value for the length of its value field.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 11 | ntp | 1:4.2.6.p5+dfsg-5 | — |
| Debian 7 | ntp | 1:4.2.6.p5+dfsg-2+deb7u2 | DSA-3154-2, DSA-3154-1 |
| Debian 6.0 | ntp | 1:4.2.6.p2+dfsg-1+deb6u2 | DLA-149-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | ntp +4 | 4.2.6p5-22.el7 | RHSA-2015:2231 |
| RHEL 6 | ntp +3 | 4.2.6p5-5.el6 | RHSA-2015:1459 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | ntp +4 | 4.2.6p5-22.el7 | ELSA-2015-2231 |
Advisories 7
- RHSA-2015:2231 Red Hat Security Advisory: ntp security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2015:1459 Red Hat Security Advisory: ntp security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-3154-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3154-2 ntp - incomplete fix Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-149-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- VDE-2022-032 AUMA: Multiple Vulnerabilities in Automation Runtime NTP Service CERT@VDE · Aug 9, 2022
- ELSA-2015-2231 Moderate: ntp security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 23, 2015
References
- VU#852879 third-party-advisory
- http://support.ntp.org/bin/view/Main/SecurityNotice#December_2014_NTP_Security_Vulne
- 72583 vdb-entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1184573
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- DSA-3388 vendor-advisory
- RHSA-2015:1459 vendor-advisory
- http://bugs.ntp.org/show_bug.cgi?id=2671
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03886en_us