Headline
CVE-2023-33192: Improper handling of NTS cookie length that could crash the ntpd-rs server
ntpd-rs is an NTP implementation written in Rust. ntpd-rs does not validate the length of NTS cookies in received NTP packets to the server. An attacker can crash the server by sending a specially crafted NTP packet containing a cookie shorter than what the server expects. The server also crashes when it is not configured to handle NTS packets. The issue was caused by improper slice indexing. The indexing operations were replaced by safer alternatives that do not crash the ntpd-rs server process but instead properly handle the error condition. A patch was released in version 0.3.3.
Impact
ntpd-rs does not validate the length of NTS cookies in received NTP packets to the server. An attacker can crash the server by sending a specially crafted NTP packet containing a cookie shorter than what the server expects. The server also crashes when it is not configured to handle NTS packets.
Patches
The issue was caused by improper slice indexing. The indexing operations were replaced by safer alternatives that do not crash the ntpd-rs server process but instead properly handle the error condition. A patch was released in version 0.3.3
Workarounds
There is no known workaround. Users are recommended to upgrade ntpd-rs as soon as possible.
References
#752
We would like to thank @mlichvar for identifying this issue
Related news
### Impact ntpd-rs does not validate the length of NTS cookies in received NTP packets to the server. An attacker can crash the server by sending a specially crafted NTP packet containing a cookie shorter than what the server expects. The server also crashes when it is not configured to handle NTS packets. ### Patches The issue was caused by improper slice indexing. The indexing operations were replaced by safer alternatives that do not crash the ntpd-rs server process but instead properly handle the error condition. A patch was released in version 0.3.3 ### Workarounds There is no known workaround. Users are recommended to upgrade ntpd-rs as soon as possible. ### References https://github.com/pendulum-project/ntpd-rs/pull/752 We would like to thank @mlichvar for identifying this issue