A Missing Authentication for Critical Function vulnerability combined with a Generation of Error Message Containing Sensitive Information vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to access sensitive system information. When a user logs in, a temporary file which contains the configuration of the device (as visible to that user) is created in the /cache folder. An unauthenticated attacker can then attempt to access such a file by sending a specific request to the device trying to guess the name of such a file. Successful exploitation will reveal configuration information. This issue affects Juniper Networks Junos OS on SRX Series and EX Series: * All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S7; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S6; * 22.1 versions earlier than 22.1R3-S5; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R1-S2, 23.2R2.