Description
ntp-keygen in ntp 4.2.8px before 4.2.8p2-RC2 and 4.3.x before 4.3.12 does not generate MD5 keys with sufficient entropy on big endian machines when the lowest order byte of the temp variable is between 0x20 and 0x7f and not #, which might allow remote attackers to obtain the value of generated MD5 keys via a brute force attack with the 93 possible keys.
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-7 | — |
| Debian 7 | ntp | 1:4.2.6.p5+dfsg-2+deb7u4 | DSA-3223-1 |
| Debian 6.0 | ntp | 1:4.2.6.p2+dfsg-1+deb6u3 | DLA-192-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | ntp | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.3 | — |
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 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | ntp | 4.2.6p5-44.1 | SUSE-SU-2015:0865-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 | ntp | 4.2.6p5-44.1 | SUSE-SU-2015:0865-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | ntp +4 | 4.2.6p5-22.el7 | ELSA-2015-2231 |
Advisories 6
- 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
- DLA-192-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3223-1 ntp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2015:0865-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2015-2231 Moderate: ntp security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 23, 2015
References
- FEDORA-2015-5830 vendor-advisory
- RHSA-2015:2231 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1210324
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- DSA-3388 vendor-advisory
- SUSE-SU-2015:1173 vendor-advisory
- 74045 vdb-entry
- http://www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
- https://bugs.ntp.org/show_bug.cgi?id=2797
- RHSA-2015:1459 vendor-advisory
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03886en_us
- http://bk1.ntp.org/ntp-stable/?PAGE=patch&REV=55199296N2gFqH1Hm5GOnhrk9Ypygg
- DSA-3223 vendor-advisory
- [oss-security] 20150423 Re: CVE request: ntp-keygen may generate non-random symmetric keys on big-endian systems mailing-list