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Fencer Intel
high 7.5

CVE-2015-3405 json

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 machi…

published 2017-08-09 9 y ago modified 2026-06-17 4 mo ago also EUVD-2015-3449

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.3%
EPSS 5.3% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

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.

Patch / fix

  • ntp Debian 11 1:4.2.6.p5+dfsg-7

debian advisories DEBIAN-CVE-2015-3405

  • ntp Ubuntu 14.04 LTS 1:4.2.6.p5+dfsg-3ubuntu2.14.04.3

ubuntu advisories UBUNTU-CVE-2015-3405

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ntp RHEL 7 4.2.6p5-22.el7
  • sntp RHEL 7 4.2.6p5-22.el7
  • ntpdate RHEL 7 4.2.6p5-22.el7
  • ntp-perl RHEL 7 4.2.6p5-22.el7
  • ntp RHEL 6 4.2.6p5-5.el6
  • ntpdate RHEL 6 4.2.6p5-5.el6
  • ntp-perl RHEL 6 4.2.6p5-5.el6

red hat advisories RHSA-2015:2231RHSA-2015:1459

  • ntp SLES for SAP 12, SLES 12, SLED 12 4.2.6p5-44.1

suse advisories SUSE-SU-2015:0865-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-3405 updated cvss 4.0

ntp: ntp-keygen may generate non-random symmetric keys on big-endian systems

  • Red Hat Enterprise Linux 5 ntp
    affected: no fix planned “Will not fix”
  • 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) sntp 4.2.6p5-22.el7, ntp-perl 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) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • 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-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-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
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Server (v. 7) ntp 4.2.6p5-22.el7, ntpdate 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux Server Optional (v. 6) ntp-perl 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Server Optional (v. 7) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux Workstation (v. 6) ntp 4.2.6p5-5.el6, ntpdate 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Workstation (v. 7) ntp 4.2.6p5-22.el7, ntpdate 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
show 2 more
  • Red Hat Enterprise Linux Workstation Optional (v. 6) ntp-perl 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Workstation Optional (v. 7) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

5.29% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.