synced 9 MIN AGO
01 Record

CVE-2015-1853

chrony before 1.31.1 does not properly protect state variables in authenticated symmetric NTP associations, which allows remote attackers with knowledge of NTP peering to cause a denial of service

UnratedPUBLISHEDCNA: redhat
CNA base scoreUnratedNo CNA CVSS vector

02 Description

chrony before 1.31.1 does not properly protect state variables in authenticated symmetric NTP associations, which allows remote attackers with knowledge of NTP peering to cause a denial of service

03 Exploitation and scoring

Exploitation
Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision
Not assessed by CISA
EPSS probability
1.69% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 76.6% of scored records. A rank, not a probability.
NVD base score
6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2019-12-09 18:53Z6 YR AGO
Last updated
2024-08-06 04:54Z2 YR AGO
Reserved
2015-02-17
Assigning CNA
redhat
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-345Insufficient Verification of Data AuthenticityClass
Data version
5.1
Document digest
6c45ba65063e6fad1d98771e2689ac8339050e209da52db1a24028b298144b9d

05 Affected products

VendorProductVersionsPlatforms
chronychronybefore 1.31.1—

06 References

07 Fixed in

Debian 12

  • chrony
    Fixed in 1.30-2

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • chrony
    Fixed in 1.30-2

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • chrony
    Fixed in 1.30-2

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 14.04 LTS

  • chrony
    Fixed in 1.29-1ubuntu0.1

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.