Integer overflow in the _authenticate function in svc_auth.c in Wind River VxWorks 5.5 through 6.9.4.1, when the Remote Procedure Call (RPC) protocol is enabled, allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a username and password.
https://www.syscan360.org/slides/2015_EN_AttackingVxWorksFromstoneagetointerstellar_Eric_Yannick.pdf