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DoS Vulnerability in ntpd-rs

Moderate severity GitHub Reviewed Published Aug 29, 2025 in pendulum-project/ntpd-rs • Updated Aug 29, 2025

Package

cargo ntpd-rs (Rust)

Affected versions

>= 1.2.0, < 1.6.2

Patched versions

1.6.2

Description

Summary

A denial of service vulnerability was discovered in ntpd-rs where an attacker can induce a message storm between two NTP servers running ntpd-rs.

Details

Since ntpd-rs version 1.2.0, when configured as a server, incorrectly responded to all NTP messages sent to the server's port with a time reply, including to responses from other servers. As a consequence, a message with a spoofed IP address of another server could cause two servers running ntpd-rs to continually respond to each other, consuming significant amounts of resources.

Impact

Any time server running ntpd-rs with version between 1.2.0 and 1.6.1 inclusive which allows non-NTS traffic is affected. Client-only configurations are not affected. Affected users are recommended to upgrade to version 1.6.2 as soon as possible.

Workarounds

Should upgrading not be possible, the impact of the issue can be mitigated by:

  • Whitelisting access to only IP addresses of clients using the server, using the ignore filter method.
  • Blocking incoming non-request traffic on the NTP server port using a firewall.
  • Disabling public access to the vulnerable NTP server
  • Disabling the server functionality by removing any [server] sections from the configuration.

Acknowledgements

The ntpd-rs authors thank Eric Sesterhenn from X41 D-Sec GmbH for finding and reporting this issue.

References

@rnijveld rnijveld published to pendulum-project/ntpd-rs Aug 29, 2025
Published to the GitHub Advisory Database Aug 29, 2025
Reviewed Aug 29, 2025
Published by the National Vulnerability Database Aug 29, 2025
Last updated Aug 29, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(16th percentile)

Weaknesses

Insufficient Control of Network Message Volume (Network Amplification)

The product does not sufficiently monitor or control transmitted network traffic volume, so that an actor can cause the product to transmit more traffic than should be allowed for that actor. Learn more on MITRE.

CVE ID

CVE-2025-58066

GHSA ID

GHSA-4855-q42w-5vr4

Source code

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