An Improper Certificate Validation weakness in the Juniper Networks Junos OS allows an attacker to perform Person-in-the-Middle (PitM) attacks when a system script is fetched from a remote source at a specified HTTPS URL, which may compromise the integrity and confidentiality of the device. The following command can be executed by an administrator via the CLI to refresh a script from a remote location, which is affected from this vulnerability: >request system scripts refresh-from (commit | event | extension-service | op | snmp) file filename url <https-url> This issue affects: Juniper Networks Junos OS All versions prior to 18.4R2-S9, 18.4R3-S9.

19.1 versions prior to 19.1R2-S3, 19.1R3-S7.

19.2 versions prior to 19.2R1-S7, 19.2R3-S3.

19.3 versions prior to 19.3R3-S4.

19.4 versions prior to 19.4R3-S7.

20.1 versions prior to 20.1R2-S2, 20.1R3.

20.2 versions prior to 20.2R3.

20.3 versions prior to 20.3R2-S1, 20.3R3.

20.4 versions prior to 20.4R2.

21.1 versions prior to 21.1R1-S1, 21.1R2.