Attackers could match phone numbers to Snapchat accounts, researchers say

A legitimate feature for finding friends on Snapchat lacks rate limiting and can be abused, a security research group claims

A security hole in popular photo messaging service Snapchat could allow attackers to find the phone numbers of many users in a short period of time, according to Gibson Security, a computer security research group.

The researchers published proof-of-concept code that abuses a legitimate feature of the Snapchat API (application programming interface) called "find_friends" to iterate through a large number of phone numbers and match them to Snapchat accounts.

Gibson Security first revealed this vulnerability in August, along with some other issues it found after reverse engineering the Snapchat API, the protocol used by Snapchat clients for Android and iOS to communicate with the company's servers.

Snapchat is a popular messaging application that also allows users to share photos, videos and drawings. It's best known for its photo self-destruct feature, where senders can specify a time period of a few seconds after which a picture viewed by the recipient is automatically deleted.

The Gibson Security researchers decided to release two exploits on Dec. 25 for the "find_friends" issue and a separate issue, because according to them, the company failed to fix the problems during the past four months.

The first exploit is a Python script that can iterate through a given set of phone numbers and return Snapchat account and display names associated with any of those numbers.

"We did some back-of-the-envelope calculations based on some number crunching we did (on an unused range of numbers)," the researchers said. "We were able to crunch through 10 thousand phone numbers (an entire sub-range in the American number format (XXX) YYY-ZZZZ -- we did the Z's -- in approximately 7 minutes on a gigabyte line on a virtual server."

The researchers estimate that an attacker could test at least 5,000 numbers per minute.

"In an entire month, you could crunch through as many as 292 million numbers with a single server," they said. "Add more servers (or otherwise increase your number crunching capabilities) and you can get through a seemingly infinite amount of numbers. It's unlikely Snapchat's end would ever be the bottleneck in this, seeing as it's run on Google App Engine, which (as we all know) is an absolute tank when it comes to handling load."

"Hopping through the particularly 'rich' area codes of America, potential malicious entities could create large databases of phone numbers and corresponding Snapchat accounts in minutes," the researchers said.

The "find_friends" feature is normally used by the Snapchat apps to help users find their friends by checking if any phone numbers in the their address books match Snapchat accounts. According to the Gibson Security researchers, the solution to prevent this feature from being abused is to enforce rate limiting for API queries.

A second issue identified by the Gibson Security researchers stems from Snapchat's lax registration requirements, which could allow attackers to register new accounts in bulk through the API. A separate script that can automate this process has been released as well.

Snapchat did not immediately respond to a request for comment.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Show Comments

Latest Videos

Conversations over a cuppa with CMO: Microsoft's Pip Arthur

​In this latest episode of our conversations over a cuppa with CMO, we catch up with the delightful Pip Arthur, Microsoft Australia's chief marketing officer and communications director, to talk about thinking differently, delivering on B2B connection in the crisis, brand purpose and marketing transformation.

More Videos

The versatility of Live Chat is really what surprises me. I’ve seen it being used not only for customer support, but also as a tool to in...

Drishti Shah

Why Bupa tapped WhatsApp for new customer messaging channel

Read more

Hi This is George, Thanks for sharing this nice information about foodpanda blockchain. During this pandemic situation food delivery indu...

George David

foodpanda launches blockchain-based out-of-home advertising campaign

Read more

Did anyone proofread this document before it was published?

Beau Ushay

CMO Momentum 2020: How to embrace agile marketing

Read more

An honest and hardworking conveyancer doesn't need a marketing strategy. His past clients will spread the word for him. These days the ho...

Bagen Andrea

What this millennial marketer is doing to shake up conveyancing

Read more

Love the post. It is so insightful for companies getting stuck in their habits and missing out on the role innovation can have on revenue...

Alessia Del Genio

How Lego built its culture of innovation, brick by brick

Read more

Blog Posts

Innovate or die

It’s hard to know if famed management and marketing guru, Peter Drucker, coined this phrase for dramatic effect. My belief is he was emphasising the notion that few products and markets are static and few organisations can survive without innovation.

Michael Valos

Senior Lecturer, Department of Marketing, Deakin University

Commissioning personas that get used

How to avoid the bottom drawer, and how to get value from the work you’ve paid for

Melanie Wiese

Chief strategy officer, Wunderman Thompson

Why It’s Going To Be A Bumper Holiday Season Despite the Pandemic

Behavioural science expert Dan Monheit, co-founder and strategy director of creative agency, Hardhat, writes that marketing chiefs should hold their nerve, as they have reason to be optimistic

Dan Monheit

Co-founder, Hardhat

Sign in