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
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
06 References
- security.gentoo.orghttps://security.gentoo.org/glsa/201507-01
- chrony.tuxfamily.orghttp://chrony.tuxfamily.org/News.html
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.