According to FireEye, the vulnerability is being exploited in the wild by the actor tracked as UNC1945.
Vulnerable component: Oracle Solaris
CVSSv3 score: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C
CWE-ID: CWE-20 - Improper Input Validation
The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.
The vulnerability exists due to improper input validation within the Pluggable authentication module (PAM) component in Oracle Solaris. A remote non-authenticated attacker can exploit this vulnerability to execute arbitrary code.
Note, this vulnerability is being actively exploited in the wild.