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Fencer Intel
medium 6.5

CVE-2015-1821 json

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possib…

published 11y ago modified 4mo ago also EUVD-2015-1941

cvss
6.5
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.4%
EPSS 3.4% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Patch / fix

  • chrony Debian 14, Debian 13, Debian 12 1.30-2

debian advisories DEBIAN-CVE-2015-1821

  • chrony Ubuntu 14.04 LTS 1.29-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2015-1821

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

  • chrony RHEL 7 2.1.1-1.el7

red hat advisories RHSA-2015:2241

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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-2015-1821 updated cvss 6.0

chrony: Heap out of bound write in address filter

  • Red Hat Enterprise Linux Client (v. 7) chrony 2.1.1-1.el7 Red Hat Enterprise Linux ComputeNode (v. 7) chrony 2.1.1-1.el7 Red Hat Enterprise Linux Server (v. 7) chrony 2.1.1-1.el7 Red Hat Enterprise Linux Workstation (v. 7) chrony 2.1.1-1.el7
    fixed: vendor fix RHSA-2015:2241

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

3.41% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

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.