CVE-2024-38528 – ntpd

Package

Manager: cargo
Name: ntpd
Vulnerable Version: >=0.3.1 <1.1.3

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00122 pctl0.32106

Details

Unlimited number of NTS-KE connections can crash ntpd-rs server ### Summary Missing limit for accepted NTS-KE connections allows an unauthenticated remote attacker to crash ntpd-rs when an NTS-KE server is configured. Non NTS-KE server configurations, such as the default ntpd-rs configuration, are unaffected. ### Details Operating systems have a limit for the number of open file descriptors (which includes sockets) in a single process, e.g. 1024 on Linux by default. When ntpd-rs is configured as an NTS server, it accepts TCP connections for the NTS-KE service. If the process has reached the descriptor limit and tries to accept a new TCP connection, the accept() system call will return with the EMFILE error and cause ntpd-rs to abort. A remote attacker can open a large number of parallel TCP connections to the server to trigger this crash. The connections need to be opened quickly enough to avoid the `key-exchange-timeout-ms` timeout (by default 1000 milliseconds). ### Impact Only NTS-KE server configuration are affected. Those without an NTS-KE server configuration such as NTS client only or NTP only configuration are unaffected. For affected configurations the ntpd-rs daemon can made completely unavailable by crashing the service. If ntpd-rs is automatically restarted, an attacker can repeat the attack to prevent ntpd-rs from doing anything useful. ### Workarounds - Disable NTS-KE server functionality - Increase system resource limits (`RLIMIT_NOFILE`) to make the attack more difficult - Lower the `key-exchange-timeout-ms` configuration setting to make the attack more difficult

Metadata

Created: 2024-06-28T21:05:52Z
Modified: 2024-07-02T02:26:15Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/06/GHSA-2xpx-vcmq-5f72/GHSA-2xpx-vcmq-5f72.json
CWE IDs: ["CWE-770"]
Alternative ID: GHSA-2xpx-vcmq-5f72
Finding: F002
Auto approve: 1