Synopsis
The remote NTP server is affected by multiple vulnerabilities.
Description
The version of the remote NTP server is 3.x or 4.x prior to 4.2.8p6.
It is, therefore, affected by the following vulnerabilities :
- A flaw exists in the receive() function due to the use of authenticated broadcast mode. A man-in-the-middle attacker can exploit this to conduct a replay attack.
(CVE-2015-7973)
- A time serving flaw exists in the trusted key system due to improper key checks. An authenticated, remote attacker can exploit this to perform impersonation attacks between authenticated peers. (CVE-2015-7974)
- An overflow condition exists in the nextvar() function due to improper validation of user-supplied input. A local attacker can exploit this to cause a buffer overflow, resulting in a denial of service condition.
(CVE-2015-7975)
- A flaw exists in ntp_control.c due to improper filtering of special characters in filenames by the saveconfig command. An authenticated, remote attacker can exploit this to inject arbitrary content. (CVE-2015-7976)
- A NULL pointer dereference flaw exists in ntp_request.c that is triggered when handling ntpdc relist commands.
A remote attacker can exploit this, via a specially crafted request, to crash the service, resulting in a denial of service condition. (CVE-2015-7977)
- A flaw exists in ntpdc that is triggered during the handling of the relist command. A remote attacker can exploit this, via recursive traversals of the restriction list, to exhaust available space on the call stack, resulting in a denial of service condition.
CVE-2015-7978)
- An unspecified flaw exists in authenticated broadcast mode. A remote attacker can exploit this, via specially crafted packets, to cause a denial of service condition.
(CVE-2015-7979)
- A flaw exists in the receive() function that allows packets with an origin timestamp of zero to bypass security checks. A remote attacker can exploit this to spoof arbitrary content. (CVE-2015-8138)
- A flaw exists in ntpq and ntpdc that allows a remote attacker to disclose sensitive information in timestamps. (CVE-2015-8139)
- A flaw exists in the ntpq protocol that is triggered during the handling of an improper sequence of numbers.
A man-in-the-middle attacker can exploit this to conduct a replay attack. (CVE-2015-8140)
- A flaw exists in the ntpq client that is triggered when handling packets that cause a loop in the getresponse() function. A remote attacker can exploit this to cause an infinite loop, resulting in a denial of service condition. (CVE-2015-8158)
Solution
Upgrade to NTP version 4.2.8p6 or later.