virtualenv is a tool for creating isolated virtual python environments. Prior to 21.7.13, the generated activate (bash and zsh) and activate

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.7.13, the generated activate (bash and zsh) and activate.fish scripts place values already escaped by shlex.quote inside an additional quoted context. In the bash and zsh script, a crafted virtual environment path reaches VIRTUAL_ENV when a relocated environment's recorded directory is absent; in the fish script, crafted Tcl or Tk library paths reach TCL_LIBRARY or TK_LIBRARY. The surplus quotes can terminate the data-only quoted run and leave shell metacharacters parsed as commands when a user sources the activation script, allowing code execution with that user's privileges. This issue is fixed in version 21.7.13.