On the Insecurity of Microsoft Office’s OOXML Signatures @ USENIX'23

09.​12.​2022 – Simon Rohlmann

At USENIX Security Symposium 2023, our paper Every Signature is Broken: On the Insecurity of Microsoft Office’s OOXML Signatures will be presented for the first time. The prepublication is already available: here.

The paper shows how signed office documents in OOXML format (Microsoft Office) can be spoofed. The OOXML specification mandates partial signatures, which the attacks exploit to arbitrarily manipulate the content of signed office documents.