This flaw allows an attacker to insert cookies at will into a running programusing libcurl, if the specific series of conditions are met.libcurl performs transfers. In its API, an application creates "easy handles"that are the individual handles for single transfers.libcurl provides a function call that duplicates en easy handle called[curl_easy_duphandle](https://curl.se/libcurl/c/curl_easy_duphandle.html).If a transfer has cookies enabled when the handle is duplicated, thecookie-enable state is also cloned - but without cloning the actualcookies. If the source handle did not read any cookies from a specific file ondisk, the cloned version of the handle would instead store the file name as`none` (using the four ASCII letters, no quotes).Subsequent use of the cloned handle that does not explicitly set a source toload cookies from would then inadvertently load cookies from a file named`none` - if such a file exists and is readable in the current directory of theprogram using libcurl. And if using the correct file format of course.
