A command injection vulnerability in install package validation subsystem of Juniper Networks Junos OS that may allow a locally authenticated attacker with privileges to execute commands with root privilege. To validate a package in Junos before installation, an administrator executes the command 'request system software add validate-on-host' via the CLI. An attacker with access to this CLI command may be able to exploit this vulnerability. This issue affects Juniper Networks Junos OS: all versions prior to 17.3R3-S10.

17.4 versions prior to 17.4R2-S12, 17.4R3-S3.

18.1 versions prior to 18.1R3-S11.

18.2 versions prior to 18.2R2-S8, 18.2R3-S6.

18.3 versions prior to 18.3R3-S4.

18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S6.

19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3.

19.2 versions prior to 19.2R3-S1.

19.3 versions prior to 19.3R2-S5, 19.3R3-S1.

19.4 versions prior to 19.4R2-S2, 19.4R3-S1.

20.1 versions prior to 20.1R2.

20.2 versions prior to 20.2R1-S2, 20.2R2.

20.3 versions prior to 20.3R1-S1, 20.3R2.