in reply to Unlink under taint mode

By using a relative path, you have an implicit dependence on $ENV{PWD}, which is tainted along with the rest of the environment. Give an absolute path if possible (by untainting $ENV{DOCUMENT_ROOT} if necessary).

After Compline,
Zaxo

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Re^2: Unlink under taint mode
by tlm (Prior) on Apr 10, 2005 at 15:16 UTC

    I don't think that's it, or at least, that's not the way it works on one Linux/Apache configuration. For one thing, $ENV{ PWD } is not even in the environment of CGI scripts (when run under Apache) in this configuration; here are the keys of %ENV, printed from within one such script: 

    AUTH_TYPE               HTTP_KEEP_ALIVE         SCRIPT_FILENAME
DOCUMENT_ROOT           HTTP_USER_AGENT         SCRIPT_NAME
GATEWAY_INTERFACE       PATH                    SERVER_ADDR
HTTP_ACCEPT             PERL5LIB                SERVER_ADMIN
HTTP_ACCEPT_CHARSET     QUERY_STRING            SERVER_NAME
HTTP_ACCEPT_ENCODING    REMOTE_ADDR             SERVER_PORT
HTTP_ACCEPT_LANGUAGE    REMOTE_PORT             SERVER_PROTOCOL
HTTP_CONNECTION         REMOTE_USER             SERVER_SIGNATURE
HTTP_COOKIE             REQUEST_METHOD          SERVER_SOFTWARE
HTTP_HOST               REQUEST_URI

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    Furthermore, if I run the CGI script listed below on my server, untainting the input filename (by passing a non-zero untaint param to the script) is sufficient to appease -T, even though I am creating and unlinking a file in a relative directory (../TRASH); if the filename is not untainted, however, -T kills the script at the unlinking step.

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    the lowliest monk

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