"Researchers Break E-Signatures in 22 Common PDF Viewers"

Researchers at Ruhr-University Bochum in Germany have revealed vulnerabilities in PDF document viewers that could allow attackers to alter documents without invalidating electronic signatures. Three different attacks that could be performed through the exploitation of these flaws have been outlined by researchers. These attacks include Universal Signature Forgery (USF), Incremental Saving Attacks (ISA), and Signature Wrapping Attacks (SWA). This article continues to discuss the vulnerability of PDF document viewers and the attacks that are possible through the abuse of this vulnerability. 

Naked Security reports "Researchers Break E-Signatures in 22 Common PDF Viewers"