A problem exists in the way the PostScript interpreter handles 
dictionaries, with various effects as follows:

(A) Regular PostScript page description programs may be affected, but it
    is unlikeky for them to be.

(B) The Ghostscript PDF interpreter does not seem to be affected, even if 
    lib\pdf_base.ps does create PostScript objects that are subject to 
    this bug.

(C) lib\pdfwrite.ps and tools based on it, like pdfinflt.ps, are affected. 
    The symptom is an "Error: /undefined in --get--", with the output 
    truncated somewhere inside the first stream's dictionary; the last 
    token written is "/File". The bug appears with encrypted PDFs; it has 
    nothing to do with encryption, but implementation details of a proc in 
    pdf_base.ps prevent it from being triggered with the unencrypted ones.

    Note:
        The same symptom, but with a completely different cause, appears 
        in bug #688152 "'Undefined in get' and extra trailer keys with 
        pdfwrite.ps and PDF1.5+".

(D) Last but not the least, this is a vulnerability that can be exploited 
    to delete any file, even in safe mode.
    - the name of the file to be deleted must be known in advance or 
      obtained by other means;
    - I *think* it cannot be exploited to read/ modify/ create files 
      without having the appropriate permissions (PermitFileXxx).