In PostgreSQL 9.3 through 11.2, the βCOPY TO/FROM PROGRAMβ function allows superusers and users in the βpg_execute_server_programβ group to execute arbitrary code in the context of the databaseβs operating system user. This functionality is enabled by default and can be abused to run arbitrary operating system commands on Windows, Linux, and macOS. NOTE: Third parties claim/state this is not an issue because PostgreSQL functionality for βCOPY TO/FROM PROGRAMβ is acting as intended. References state that in PostgreSQL, a superuser can execute commands as the server user without using the βCOPY FROM PROGRAMβ.
packetstormsecurity.com/files/152757/PostgreSQL-COPY-FROM-PROGRAM-Command-Execution.html
packetstormsecurity.com/files/166540/PostgreSQL-11.7-Remote-Code-Execution.html
packetstormsecurity.com/files/171722/PostgreSQL-9.6.1-Remote-Code-Execution.html
blog.hagander.net/when-a-vulnerability-is-not-a-vulnerability-244/
medium.com/greenwolf-security/authenticated-arbitrary-command-execution-on-postgresql-9-3-latest-cd18945914d5
paquier.xyz/postgresql-2/postgres-9-3-feature-highlight-copy-tofrom-program/
security.netapp.com/advisory/ntap-20190502-0003/
www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/authenticated-arbitrary-command-execution-on-postgresql-9-3/