Junos OS: Insufficient authentication for user login when a specific system configuration error occurs.

Summary

A specific device configuration can result in a commit failure condition. When this occurs, a user is logged in without being prompted for a password while trying to login through console, ssh, ftp, telnet or su, etc., This issue relies upon a device configuration precondition to occur. Typically, device configurations are the result of a trusted administrative change to the system's running configuration. The following error messages may be seen when this failure occurs: mgd: error: commit failed: (statements constraint check failed) Warning: Commit failed, activating partial configuration. Warning: Edit the router configuration to fix these errors. If the administrative changes are not made that result in such a failure, then this issue is not seen. No other Juniper Networks products or platforms are affected by this issue. Affected releases are Juniper Networks Junos OS 12.3 prior to 12.3R10, 12.3R11; 12.3X48 prior to 12.3X48-D20; 13.2 prior to 13.2R8; 13.3 prior to 13.3R7; 14.1 prior to 14.1R4-S12, 14.1R5, 14.1R6; 14.1X53 prior to 14.1X53-D30; 14.2 prior to 14.2R4; 15.1 prior to 15.1F2, 15.1F3, 15.1R2.