Mlichvar

**Name of the Vulnerable Software and Affected Versions** nptd-rs versions prior to 1.1.3 **Description** The issue is related to a missing limit for accepted NTS-KE connections in nptd-rs, a tool for synchronizing computer clocks that implements the NTP and NTS protocols. This allows an unauthenticated remote attacker to crash nptd-rs when an NTS-KE server is configured. Configurations without an NTS-KE server, such as the default ntpd-rs configuration or NTP only configurations, are unaffected. A remote attacker can trigger this crash by opening a large number of parallel TCP connections to the server, potentially making the ntpd-rs daemon completely unavailable. **Recommendations** For versions prior to 1.1.3, update to version 1.1.3 to resolve the issue. As a temporary workaround, consider disabling the NTS-KE server functionality to prevent exploitation. Additionally, increasing system resource limits (RLIMIT NOFILE) or lowering the key-exchange-timeout-ms configuration setting can make the attack more difficult.

**Name of the Vulnerable Software and Affected Versions** ntpd-rs versions prior to 0.3.3 **Description** 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, which was replaced by safer alternatives to handle the error condition properly. **Recommendations** For versions prior to 0.3.3, upgrade to version 0.3.3 or later to resolve the issue. As a temporary workaround, consider configuring ntpd-rs to run purely as an NTP client, as this mode is not affected by the issue. For machines where serving the time is required, upgrade ntpd-rs as soon as possible, as there is no known workaround.