Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Application Security

9/12/2019
05:15 PM
Connect Directly
Twitter
LinkedIn
Google+
RSS
E-Mail
50%
50%

Instagram Bug Put User Account Details, Phone Numbers at Risk

The vulnerability, now patched, is the latest in a series of bad news for Facebook.

A now-patched Instagram vulnerability could have exposed users' account data and phone numbers to cyberattackers, parent company Facebook confirmed in a new report from Forbes.

The bug was discovered by an Israeli hacker who goes by the handle @ZHacker13. It could have potentially been used to access user data including names, full phone numbers, and Instagram account numbers and handles – all an attacker needs to narrow their focus on a specific person.

It's the latest in a series of bad news for Facebook, which recently patched an account-takeover flaw in Instagram that would have let an attacker take over any account by resetting its password. Earlier this month, 419 million phone numbers belonging to Facebook users were found publicly accessible in a third-party database left online without password protection.

This particular vulnerability existed in Instagram's contact importer, which, when subject to brute force attacks, could grant an attacker access to the data. An attacker could use an algorithm to verify individual phone numbers to see which are linked to an Instagram account. Exploiting a second process could give them the name and number linked to the phone number, enabled by the Sync Contacts tool that lets users find their contacts on the platform.

In theory, an attacker could leverage a wealth of bots to brute force Instagram's login form and collect legitimate phone numbers, Forbes points out in its report. Instagram caps syncing to three times per day, per account; however, an attacker with enough bots could bypass this limitation. While this bug was difficult to exploit, it was possible for an attacker to build a collection of user data.

"This vulnerability further demonstrates the over-reliance of phone numbers as a strong form of authentication to digital platforms like Instagram," said Zack Allen, director of threat operations at ZeroFox, who in an email called the importance of phone numbers as identifiers on modern Internet platforms "harrowing."

"A database such as the one leaked last week with millions of phone numbers, and a vulnerability like this to tie accounts to phone numbers, sets a dangerous precedent for those vulnerable to SIM swaps," he added.

@ZHacker13 shared his findings with Facebook in early August. Facebook initially responded, saying these types of vulnerabilities, which show a given email address or phone number is linked with a specific account, are "extremely low risk." However, bugs that let an attacker figure out which user ID an email address or phone number is linked to are another story.

After further communication in which the company reportedly expressed little urgency to fix the problem, Facebook told @ZHacker13 this was "a valid issue." It has now addressed the problem; the researcher has tested his exploit and confirmed with Forbes it no longer works. There has not yet been evidence indicating account data was misused as a result of the vulnerability.

Related Content:

Check out The Edge, Dark Reading's new section for features, threat data, and in-depth perspectives. Today's top story: "Community Projects Highlight Need for Security Volunteers."

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Data Privacy Protections for the Most Vulnerable -- Children
Dimitri Sirota, Founder & CEO of BigID,  10/17/2019
Sodinokibi Ransomware: Where Attackers' Money Goes
Kelly Sheridan, Staff Editor, Dark Reading,  10/15/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
7 Threats & Disruptive Forces Changing the Face of Cybersecurity
This Dark Reading Tech Digest gives an in-depth look at the biggest emerging threats and disruptive forces that are changing the face of cybersecurity today.
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-18214
PUBLISHED: 2019-10-19
The Video_Converter app 0.1.0 for Nextcloud allows denial of service (CPU and memory consumption) via multiple concurrent conversions because many FFmpeg processes may be running at once. (The workload is not queued for serial execution.)
CVE-2019-18202
PUBLISHED: 2019-10-19
Information Disclosure is possible on WAGO Series PFC100 and PFC200 devices before FW12 due to improper access control. A remote attacker can check for the existence of paths and file names via crafted HTTP requests.
CVE-2019-18209
PUBLISHED: 2019-10-19
templates/pad.html in Etherpad-Lite 1.7.5 has XSS when the browser does not encode the path of the URL, as demonstrated by Internet Explorer.
CVE-2019-18198
PUBLISHED: 2019-10-18
In the Linux kernel before 5.3.4, a reference count usage error in the fib6_rule_suppress() function in the fib6 suppression feature of net/ipv6/fib6_rules.c, when handling the FIB_LOOKUP_NOREF flag, can be exploited by a local attacker to corrupt memory, aka CID-ca7a03c41753.
CVE-2019-18197
PUBLISHED: 2019-10-18
In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclo...