Entries Tagged "Adobe"

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Windows Access Control

I just found an interesting paper: “Windows Access Control Demystified,” by Sudhakar Govindavajhala and Andrew W. Appel. Basically, they show that companies like Adobe, Macromedia, etc., have mistakes in their Access Control Programming that open security holes in Windows XP.

Abstract

In the Secure Internet Programming laboratory at Princeton University, we have been investigating network security management by using logic programming. We developed a rule based framework—Multihost, Multistage, Vulnerability Analysis(MulVAL)—to perform end-to-end, automatic analysis of multi-host, multi-stage attacks on a large network where hosts run different operating systems. The tool finds attack paths where the adversary will have to use one or more than one weaknesses (buffer overflows) in multiple software to attack the network. The MulVAL framework has been demonstrated to be modular, flexible, scalable and efficient [20]. We applied these techniques to perform security analysis of a single host with commonly used software.

We have constructed a logical model of Windows XP access control, in a declarative but executable (Datalog) format. We have built a scanner that reads access-control conguration information from the Windows registry, file system, and service control manager database, and feeds raw conguration data to the model. Therefore we can reason about such things as the existence of privilege-escalation attacks, and indeed we have found several user-to-administrator vulnerabilities caused by misconfigurations of the access-control lists of commercial software from several major vendors. We propose tools such as ours as a vehicle for software developers and system administrators to model and debug the complex interactions of access control on installations under Windows.

EDITED TO ADD (2/13): Ed Felten has some good commentary about the paper on his blog.

Posted on February 13, 2006 at 12:11 PMView Comments

The NSA on How to Redact

Interesting paper.

Both the Microsoft Word document format (MS Word) and Adobe Portable Document (PDF) are complex, sophisticated computer data formats. They can contain many kinds of information such as text, graphics, tables, images, meta-data, and more all mixed together. The complexity makes them potential vehicles for exposing information unintentionally, especially when downgrading or sanitizing classified materials. Although the focus is on MS Word, the general guidance applies to other word processors and office tools, such as WordPerfect, PowerPoint, Excel, Star Office, etc.

This document does not address all the issues that can arise when distributing or downgrading original document formats such as MS Word or MS PowerPoint. Using original source formats, such as MS Word, for downgrading can entail exceptional risks; the lengthy and complicated procedures for mitigating such risks are outside the scope of this note.

EDITED TO ADD (2/1): The NSA page for the redaction document, and other “Security Configuration Guides,” is here.

Posted on February 1, 2006 at 1:09 PMView Comments

PDF Redacting Failure

I wasn’t going to even bother writing about this, but I got too many e-mails from people.

We all know that masking over the text of a PDF document doesn’t actually erase the underlying text, right?

Don’t we?

Seems like we don’t.

Italian media have published classified sections of an official US military inquiry into the accidental killing of an Italian agent in Baghdad.

A Greek medical student at Bologna University who was surfing the web early on Sunday found that with two simple clicks of his computer mouse he could restore censored portions of the report.

Posted on May 3, 2005 at 9:11 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.