Thingiverse Data Leaked — Check Your Passwords

October 14, 2021 by Jenny List 40 Comments

Every week seems to bring another set of high-profile data leaks, and this time it’s the turn of a service that should be of concern to many in our community. A database backup from the popular 3D model sharing website Thingiverse has leaked online, containing 228,000 email addresses, full names, addresses, and passwords stored as unsalted SHA-1 or bcrypt hashes. If you have an account with Thingiverse it is probably worth your while to head over to Have I Been Pwned to search on your email address, and just to be sure you should also change your password on the site. Our informal testing suggests that not all accounts appear to be contained in the leak, which appears to relate to comments left on the site.

Aside from the seriousness of a leak in itself, the choice of encryption should raise a few eyebrows. Both SHA-1 and bcrypt can be considered broken or at best vulnerable to attack here in 2021, so much so that for any website to have avoided migration to a stronger algorithm indicates a very poor attention to website security on the part of Thingiverse. We’d like to think that it would serve as a salutary warning to other website operators in our field, to review and upgrade their encryption, but we suspect readers will agree that this won’t be the last time we report on such a leak and nervously check our own login details.

Netscape Communicator And SHA-1 Written Into Brexit Agreement

December 28, 2020 by Jenny List 36 Comments

We pity the civil servants involved in the negotiations between the European Union and the United Kingdom, because after tense meetings until almost the Eleventh Hour, they’ve had to cobble together the text of a post-Brexit trade agreement in next-to-no time. In the usual manner of such international agreements both sides are claiming some kind of victory over fish, but the really interesting parts of the document lie in the small print. In particular it was left to eagle-eyed security researchers to spot that Netscape Communicator 4, SHA-1, and RSA encryption with a 1024-bit key length are recommended to secure the transfer of DNA data between states. The paragraphs in question can be found on page 932 of the 1256-page agreement.

It’s likely that some readers under 30 years old will never have used a Netscape product even though they will be familiar with Firefox, the descendant Mozilla software. Netscape were a pioneer of early web browsers, and Communicator 4 was the company’s all-in-one browser and email offering from the late 1990s. It and its successors steadily lost ground against Microsoft’s Internet Explorer, and ultimately faded away along with the company under AOL ownership in the late 2000s. Meanwhile the SHA-1 hashing algorithm has been demonstrated to be vulnerable to collision attacks, and computing power has advanced such that 1024-bit RSA encryption can be broken in a sensible time frame by anyone with sufficient GPU power to give it a try. It’s clear that something is amiss in the drafting of this treaty, and we’d go so far as to venture the opinion that a tired civil servant simply cut-and-pasted from a late-1990s security document.

So will the lawmakers of Europe now have to dig for ancient software as mandated by treaty? We hope not, as from our reading they are given as examples rather than as directives. We worry however that their agencies might turn out to be as clueless on digital security as evidently the civil servants are, so maybe Verizon Communications, current owners of the Netscape brand, could be in for a few support calls.

SHAttered — SHA-1 Is Broken In

February 23, 2017 by Pedro Umbelino 96 Comments

A team from Google and CWI Amsterdam just announced it: they produced the first SHA-1 hash collision. The attack required over 9,223,372,036,854,775,808 SHA-1 computations, the equivalent processing power as 6,500 years of single-CPU computations and 110 years of single-GPU computations. While this may seem overwhelming, this is a practical attack if you are, lets say, a state-sponsored attacker. Or if you control a large enough botnet. Or if you are just able to spend some serious money on cloud computing. It’s doable. Make no mistake, this is not a brute-force attack, that would take around 12,000,000 single-GPU years to complete.

SHA-1 is a 160bit standard cryptographic hash function that is used for digital signatures and file integrity verification in a wide range of applications, such as digital certificates, PGP/GPG signatures, software updates, backup systems and so forth. It was, a long time ago, proposed as a safe alternative to MD5, known to be faulty since 1996. In 2004 it was shown that MD5 is not collision-resistant and not suitable for applications like SSL certificates or digital signatures. In 2008, a team of researchers demonstrated how to break SSL based on MD5, using 200 Playstations 3.

Early since 2005 theoretical attacks against SHA-1 were known. In 2015 an attack on full SHA-1 was demonstrated (baptized the SHAppening). While this did not directly translate into a collision on the full SHA-1 hash function due to some technical aspects, it undermined the security claims for SHA-1. With this new attack, dubbed SHAttered, the team demonstrated a practical attack on the SHA-1 algorithm, producing two different PDF files with the same checksum.

The full working code will be released in three months, following Google’s vulnerability disclosure policy, and it will allow anyone to create a pair of PDFs that hash to the same SHA-1 sum given two distinct images and some, not yet specified, pre-conditions.

For now, recommendations are to start using SHA-256 or SHA-3 on your software. Chrome browser already warns if a website has SHA-1 certificate, Firefox and the rest of the browsers will surely follow. Meanwhile, as always, tougher times are ahead for legacy systems and IoT like devices.

25C3: Hackers Completely Break SSL Using 200 PS3s

December 30, 2008 by Eliot 78 Comments

A team of security researchers and academics has broken a core piece of internet technology. They made their work public at the 25th Chaos Communication Congress in Berlin today. The team was able to create a rogue certificate authority and use it to issue valid SSL certificates for any site they want. The user would have no indication that their HTTPS connection was being monitored/modified.

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