NTP BUG 3414: ntpq: decodearr() can write beyond its buf limits

Last update: June 27, 2022 20:45 UTC (51d68a4aa)

Summary

Resolved 27 Feb 2018 DATE
References Bug 3414 CVE-2018-7183
Affects ntpq in ntp-4.2.8p6, up to but not including ntp-4.2.8p11. Resolved in 4.2.8p11.
CVSS2 Score MED 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
CVSS3 Score MED 5.0 CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

Description

ntpq is a monitoring and control program for ntpd. decodearr() is an internal function of ntpq that is used to – wait for it – decode an array in a response string when formatted data is being displayed. This is a problem in affected versions of ntpq if a maliciously-altered ntpd returns an array result that will trip this bug, or if a bad actor is able to read an ntpq request on its way to a remote ntpd server and forge and send a response before the remote ntpd sends its response. It’s potentially possible that the malicious data could become injectable/executable code.

Mitigation

Credit

This weakness was discovered by Michael Macnair of Thales e-Security.

Timeline