A flaw was found in perl-GD. A remote attacker could exploit this vulnerability by providing specially crafted filenames to functions that open files. This issue arises because the `_make_filehandle` function uses Perl's 2-argument `open()` with untrusted input, allowing special characters like pipes or redirects to be interpreted as commands or file operations. Successful exploitation could lead to arbitrary command execution or unauthorized file modification under the privileges of the affected process.
GD versions before 2.86 for Perl allow OS command injection and file overwrite via a 2-arg open() of filename arguments in _make_filehandle.
GD::Image::_make_filehandle opens a filename argument with Perl's 2-arg open(), so a filename that begins or ends with a pipe ("| cmd", "cmd |") or begins with a redirect ("> path", ">> path") is run as a command or redirect rather than opened as a file. _make_filehandle is the single open path behind every filename-accepting constructor (new, newFromPng, newFromJpeg, and the rest); the in-memory *Data variants do not open a path and are unaffected.
Any caller that forwards untrusted input to one of these constructors as a pathname can run an arbitrary command or truncate a file under the process UID.
GD versions before 2.86 for Perl allow OS command injection and file overwrite via a 2-arg open() of filename arguments in _make_filehandle. GD::Image::_make_filehandle opens a filename argument with Perl's 2-arg open(), so a filename that begins or ends with a pipe ("| cmd", "cmd |") or begins with a redirect ("> path", ">> path") is run as a command or redirect rather than opened as a file. _make_filehandle is the single open path behind every filename-accepting constructor (new, newFromPng, newFromJpeg, and the rest); the in-memory *Data variants do not open a path and are unaffected. Any caller that forwards untrusted input to one of these constructors as a pathname can run an arbitrary command or truncate a file under the process UID.