Network Time Protocol Authenticated Mode 6 Packet Processing NULL Pointer Dereference Vulnerability

A vulnerability in Network Time Protocol (NTP) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability is due to improper processing of crafted authenticated mode 6 (ntpq) packets by the affected software. An attacker who is able to authenticate a packet with a private key that is used for mode 6 authorization could exploit this vulnerability by sending a packet that submits malicious input to the targeted system. A successful exploit could trigger a NULL pointer dereference condition causing the ntpd daemon to crash, resulting in a DoS condition.

Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available. has confirmed the vulnerability and released software updates.

Security Impact Rating: Medium

CVE: CVE-2019-8936

Source:: Cisco Multivendor Vulnerability Alerts