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Improper handling of NTS cookie length that could crash the ntpd-rs server

High severity GitHub Reviewed Published May 25, 2023 in pendulum-project/ntpd-rs • Updated Nov 4, 2023

Package

cargo ntpd (Rust)

Affected versions

>= 0.3.0, < 0.3.3

Patched versions

0.3.3

Description

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.

ntpd-rs running purely as an ntp client is not affected.

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

ntpd-rs running purely as an ntp client is not affected. By default, ntpd-rs packages are not configured to run as a server.

For machines where serving the time is required, there is no known workaround. Users are recommended to upgrade ntpd-rs as soon as possible.

References

pendulum-project/ntpd-rs#752

We would like to thank @mlichvar for identifying this issue

References

@rnijveld rnijveld published to pendulum-project/ntpd-rs May 25, 2023
Published to the GitHub Advisory Database May 25, 2023
Reviewed May 25, 2023
Published by the National Vulnerability Database May 27, 2023
Last updated Nov 4, 2023

Severity

High

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
High

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:H

EPSS score

0.138%
(51st percentile)

Weaknesses

CVE ID

CVE-2023-33192

GHSA ID

GHSA-qwhm-h7v3-mrjx

Source code

Credits

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