CVE-2015-1853 Denial of service in chrony
Remote attackers can cause denial of service in chrony NTP servers by sending crafted packets with random timestamps, preventing time synchronization.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2015-1853?
CVE-2015-1853 is a medium-severity denial of service vulnerability in chrony, published on 9 Dec 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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 (inability to synchronize) via random timestamps in crafted NTP data packets.
Which versions are affected by CVE-2015-1853?
It affects 1 product.
Products include Tuxfamily Chrony.
How do I fix CVE-2015-1853?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2015-1853 being exploited?
There is no known exploitation of CVE-2015-1853 in the wild and no public exploit code.
Other vulnerabilities in chrony
Sources
Also known as DEBIAN-CVE-2015-1853, GHSA-gf8j-j7q8-vhh5, UBUNTU-CVE-2015-1853.