Skip to content
Fencer Intel
medium 6.5

CVE-2015-7855 json

The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service…

published 9y ago modified 4mo ago also EUVD-2015-7753

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
31.1%
EPSS 31.1% chance of exploitation in 30 days, percentile 98%
public exploits
1
Exploit-DB

Summary

The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (assertion failure) via a 6 or mode 7 packet containing a long data value.

Patch / fix

  • ntp ntp 4.2.8, 4.3.77
  • ntp Debian 11 1:4.2.8p4+dfsg-1

debian advisories DEBIAN-CVE-2015-7855

  • ntp Ubuntu 14.04 LTS 1:4.2.6.p5+dfsg-3ubuntu2.14.04.5

ubuntu advisories UBUNTU-CVE-2015-7855

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 SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLES 11 SP2-LTSS +3 more 4.2.8p6-41.1
  • ntp SLES for SAP 12, SLES 12, SLED 12 4.2.8p6-46.5.2
  • yast2-ntp-client SLES for SAP 12, SLES 12, SLED 12 +1 more 3.1.12.4-8.2
  • ntp SLES for SAP 11 SP4, SLES 11 SP4, SLED 11 SP4 4.2.8p4-5.1
  • yast2-ntp-client SLES 11 SP2-LTSS 2.17.14.1-1.12.1

suse advisories SUSE-SU-2016:1311-1SUSE-SU-2016:1247-1SUSE-SU-2015:2058-1

  • ntp openSUSE Tumbleweed 4.2.8p9-1.1

opensuse advisories openSUSE-SU-2024:10181-1

Is CVE-2015-7855 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2015-7855 updated cvss 3.5

ntp: ASSERT in decodenetnum() on invalid values

  • Red Hat Enterprise Linux 5 ntp Red Hat Enterprise Linux 6 ntp, ntpdate, ntp-perl Red Hat Enterprise Linux 7 ntp, sntp, ntpdate, ntp-perl
    not affected: vulnerable code not present

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

cisa ICSA-21-103-11 updated cvss 6.5

Siemens TIM 4R-IE Devices

  • Siemens SIPLUS NET TIM 4R-IE (6AG1800-4BA00-7AA0) Siemens SIPLUS NET TIM 4R-IE DNP3 (6AG1803-4BA00-7AA0) Siemens TIM 4R-IE (6NH7800-4BA00) Siemens TIM 4R-IE DNP3 (6NH7803-4BA00-0AA0)
    affected: workaround, no fix planned

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-15-356-01 updated cvss 2.2

Siemens RUGGEDCOM ROX-based Devices NTP Vulnerabilities

  • Siemens ROX II <2.9.0 Siemens RUGGEDCOM ROX I
    affected: mitigation “Update to the latest version. (http://www.siemens.com/automation/support-request)”

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Timeline

  1. First public exploit (EDB-40840)
  2. Published

Exploit prediction

31.07% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-40840 NTP 4.2.8p3 - Denial of Service dos, 2016-11-28

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P

Classification

Weakness
  • CWE-20 Improper Input Validation

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.