Practical Decryption exFiltration: Breaking PDF Encryption

@article{Mller2019PracticalDE,
  title={Practical Decryption exFiltration: Breaking PDF Encryption},
  author={Jens M{\"u}ller and Fabian Ising and Vladislav Mladenov and Christian Mainka and Sebastian Schinzel and J{\"o}rg Schwenk},
  journal={Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Security},
  year={2019}
}
The Portable Document Format, better known as PDF, is one of the most widely used document formats worldwide, and in order to ensure information confidentiality, this file format supports document encryption. In this paper, we analyze PDF encryption and show two novel techniques for breaking the confidentiality of encrypted documents. First, we abuse the PDF feature of partially encrypted documents to wrap the encrypted part of the document within attacker-controlled content and therefore… 
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References

SHOWING 1-10 OF 56 REFERENCES
1 Trillion Dollar Refund: How To Spoof PDF Signatures
TLDR
This paper presents the first comprehensive security evaluation on digital signatures in PDFs, and introduces three novel attack classes which bypass the cryptographic protection of digitally signed PDF files allowing an attacker to spoof the content of a signed PDF.
Hiding Malicious Content in PDF Documents
This paper is a proof-of-concept demonstration for a specific digital signatures vulnerability that shows the ineffectiveness of the WYSIWYS (What You See Is What You Sign) concept. The algorithm is
On The (In-)Security Of JavaScript Object Signing And Encryption
TLDR
This work introduces JOSEPH (JavaScript Object Signing and Encryption Pentesting Helper) -- the authors' newly developed Burp Suite extension, which automatically performs security analysis on targeted applications, and finds severe vulnerabilities in six popular JOSE libraries.
Malicious URI resolving in PDF documents
  • V. Hamon
  • Computer Science
    Journal of Computer Virology and Hacking Techniques
  • 2013
TLDR
It’s shown that the simple use of an HTTP request from a PDF can be a pretty good vector for an attacker and how it can be relatively easy to reuse some vulnerabilities from outside the document.
One Bad Apple: Backwards Compatibility Attacks on State-of-the-Art Cryptography
TLDR
This work shows the less obvious fact that even if users have the best of intentions to use only the most upto-date, vulnerability-free version of a system, the mere existence of support for old versions can have a catastrophic effect on security.
Dancing on the Lip of the Volcano: Chosen Ciphertext Attacks on Apple iMessage
TLDR
This paper outlines a novel chosen ciphertext attack on Huffman compressed data, which allows retrospective decryption of some iMessage payloads in less than 218 queries and describes mitigations that will prevent these attacks on the protocol, without breaking backwards compatibility.
Re: What's Up Johnny? - Covert Content Attacks on Email End-to-End Encryption
TLDR
It is demonstrated how the attacker can unknowingly abuse the user as a decryption oracle by replying to an unsuspicious looking email, and the plaintext of hundreds of encrypted emails can be leaked at once.
Efail: Breaking S/MIME and OpenPGP Email Encryption using Exfiltration Channels
TLDR
Novel attacks built upon a technique the authors call malleability gadgets to reveal the plaintext of encrypted emails are described, which use CBC/CFB gadgets to inject malicious plaintext snippets into encrypted emails.
How to Break Microsoft Rights Management Services
TLDR
A security analysis of Microsoft RMS is provided and two working attacks are presented that show that in contrast to claims made by Microsoft, Microsoft R MS can only be used to enforce all-or-nothing access.
Malicious origami in PDF
TLDR
The PDF language and its security model is presented, and then the market leader of PDF software, Acrobat Reader is presented: how this format can be used for malicious purposes is shown.
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