Securing Your Smartphone
This is part 3 of Sean Gallagher’s advice for “securing your digital life.”
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This is part 3 of Sean Gallagher’s advice for “securing your digital life.”
ArsTechnica’s Sean Gallagher has a two–part article on “securing your digital life.”
It’s pretty good.
Interesting research: “Who Can Find My Devices? Security and Privacy of Apple’s Crowd-Sourced Bluetooth Location Tracking System“:
Abstract: Overnight, Apple has turned its hundreds-of-million-device ecosystem into the world’s largest crowd-sourced location tracking network called offline finding (OF). OF leverages online finder devices to detect the presence of missing offline devices using Bluetooth and report an approximate location back to the owner via the Internet. While OF is not the first system of its kind, it is the first to commit to strong privacy goals. In particular, OF aims to ensure finder anonymity, untrackability of owner devices, and confidentiality of location reports. This paper presents the first comprehensive security and privacy analysis of OF. To this end, we recover the specifications of the closed-source OF protocols by means of reverse engineering. We experimentally show that unauthorized access to the location reports allows for accurate device tracking and retrieving a user’s top locations with an error in the order of 10 meters in urban areas. While we find that OF’s design achieves its privacy goals, we discover two distinct design and implementation flaws that can lead to a location correlation attack and unauthorized access to the location history of the past seven days, which could deanonymize users. Apple has partially addressed the issues following our responsible disclosure. Finally, we make our research artifacts publicly available.
There is also code available on GitHub, which allows arbitrary Bluetooth devices to be tracked via Apple’s Find My network.
Really interesting research:
“Exploitation and Sanitization of Hidden Data in PDF Files”
Abstract: Organizations publish and share more and more electronic documents like PDF files. Unfortunately, most organizations are unaware that these documents can compromise sensitive information like authors names, details on the information system and architecture. All these information can be exploited easily by attackers to footprint and later attack an organization. In this paper, we analyze hidden data found in the PDF files published by an organization. We gathered a corpus of 39664 PDF files published by 75 security agencies from 47 countries. We have been able to measure the quality and quantity of information exposed in these PDF files. It can be effectively used to find weak links in an organization: employees who are running outdated software. We have also measured the adoption of PDF files sanitization by security agencies. We identified only 7 security agencies which sanitize few of their PDF files before publishing. Unfortunately, we were still able to find sensitive information within 65% of these sanitized PDF files. Some agencies are using weak sanitization techniques: it requires to remove all the hidden sensitive information from the file and not just to remove the data at the surface. Security agencies need to change their sanitization methods.
Short summary: no one is doing great.
The NSA’s Cybersecurity Directorate—that’s the part that’s supposed to work on defense—has released two documents (a full and an abridged version) on securing virtual private networks. Some of it is basic, but it contains good information.
Maintaining a secure VPN tunnel can be complex and requires regular maintenance. To maintain a secure VPN, network administrators should perform the following tasks on a regular basis:
- Reduce the VPN gateway attack surface
- Verify that cryptographic algorithms are Committee on National Security Systems Policy (CNSSP) 15-compliant
- Avoid using default VPN settings
- Remove unused or non-compliant cryptography suites
- Apply vendor-provided updates (i.e. patches) for VPN gateways and clients
New research: “Security Analysis of the Democracy Live Online Voting System“:
Abstract: Democracy Live’s OmniBallot platform is a web-based system for blank ballot delivery, ballot marking, and (optionally) online voting. Three states—Delaware, West Virginia, and New Jersey—recently announced that they will allow certain voters to cast votes online using OmniBallot, but, despite the well established risks of Internet voting, the system has never been the subject of a public, independent security review.
We reverse engineered the client-side portion of OmniBallot, as used in Delaware, in order to detail the system’s operation and analyze its security.We find that OmniBallot uses a simplistic approach to Internet voting that is vulnerable to vote manipulation by malware on the voter’s device and by insiders or other attackers who can compromise Democracy Live, Amazon,Google, or Cloudflare. In addition, Democracy Live, which appears to have no privacy policy, receives sensitive personally identifiable information—including the voter’s identity, ballot selections, and browser fingerprint—that could be used to target political ads or disinformation campaigns.Even when OmniBallot is used to mark ballots that will be printed and returned in the mail, the software sends the voter’s identity and ballot choices to Democracy Live, an unnecessary security risk that jeopardizes the secret ballot. We recommend changes to make the platform safer for ballot delivery and marking. However, we conclude that using OmniBallot for electronic ballot return represents a severe risk to election security and could allow attackers to alter election results without detection.
News story.
EDITED TO ADD: This post has been translated into Portuguese.
Sidebar photo of Bruce Schneier by Joe MacInnis.