An Improper Neutralization of Data within XPath Expressions ('XPath Injection') vulnerability in J-Web shipped with Juniper Networks Junos OS allows an unauthenticated, network-based attacker to execute remote commands on the target device.  While an administrator is logged into a J-Web session or has previously logged in and subsequently logged out of their J-Web session, the attacker can arbitrarily execute commands on the target device with the other user's credentials. In the worst case, the attacker will have full control over the device. This issue affects Junos OS:  * All versions before 21.2R3-S8,  * from 21.4 before 21.4R3-S7, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S2, * from 23.2 before 23.2R2, * from 23.4 before 23.4R1-S1, 23.4R2.