WhatsApp, Instagram and Facebook appeared to be returning to life after being down for hours – with the outage completely preventing users from accessing the services and causing huge embarrassment for one of the world’s biggest technology companies.
The disruption, which hit Facebook’s platforms minutes before 5pm UK time (or 9am on the US West Coast, where the company has its San Francisco Bay Area headquarters), came a day after a whistleblower accused the firm of repeatedly prioritising profit over clamping down on hate speech and misinformation.
By around midnight UK time, users were able to access Facebook and Instagram from late on Monday evening, but many still faced problems on WhatsApp.
We’re aware that some people are having trouble accessing our apps and products. We’re working to get things back to normal as quickly as possible, and we apologize for any inconvenience.
— Andy Stone (@andymstone) October 4, 2021
What happened?
According to web service monitoring platform DownDetector, thousands of people reported outages before 5pm.
Data on its website showed that almost 50,000 people had reported the outages on Facebook.
Most complaints cited issues with the website (72%), while others were linked to issues with the server connection and the app.
More than 75,000 had complained about WhatsApp, with 43% reporting issues with the app itself, while 28% cited the server connection and 28% relating to sending messages.
More than 30,000 Instagram users also had similar complaints, with 51% relating to the app, 26% over the server connection and 23% citing the website.
A graph on the DownDetector website showed a clear spike from after 4pm.
Several users using their Facebook credentials to log in to third-party apps – such as Pokemon Go and Match Masters – were also facing issues.
According to The New York Times, the outage also took out Workplace, the company’s internal communications platform. Additionally, employees reportedly couldn’t receive external emails at the moment.
What was the problem?
Facebook has not said what was causing the outage – but technology journalists and security experts seemed to think there was an issue with the system that tells your phone or computer how to connect with the sites.
Specifically, it was to do with the Domain Name System (DNS), which translates an address like “http://facebook.com” to an IP address like 123.45.67.890, or put another way, allows web addresses to take users to their destinations.
Facebook itself controls the relevant settings. A similar outage at cloud company Akamai Technologies Inc took down multiple websites in July.
According to reports, the DNS records that take people to Facebook and Instagram were withdrawn on Monday, meaning the sites were inaccessible. The claim has not been confirmed by the US firm.
According to journalist Brian Krebs, who covers cybercrime and security, "the [Domain Name System] records that tell systems how to find https://t.co/0yjNBD8zNW or https://t.co/1nzy4ROcvI got withdrawn this morning from the global routing tables." pic.twitter.com/Hb6lJjrg1r
— BuzzFeed (@BuzzFeed) October 4, 2021
To be more precise (and Geek Factor 5) the BGP routes serving Facebook's authoritative DNS were withdrawn, rendering all Facebook domains inaccessible. That's per @DougMadory , who knows a few things about BGP/DNS.
— briankrebs (@briankrebs) October 4, 2021
An outside hack was viewed as less likely. Two Facebook security team members told The New York Times, speaking on the condition of anonymity, it was unlikely to be related to a cybersecurity attack.
A massive denial-of-service attack that could overwhelm one of the world’s most popular sites would require either coordination among powerful criminal groups or a very innovative technique.
Cyber security specialist Jake Moore told the PA news agency: “There have been many reports and I’m struggling to find out exactly what has happened - I’m reading it could be DNS related, which means there is an issue with the connection not knowing where to go to your device.
“It could well be a human error or a software bug lurking in the shadows but whatever it is Facebook needs to do its best to mitigate the problem of causing more panic about this.
“The biggest problem is fears over a cyber attack but as we saw from Fastly in the summer I would hedge my bets on that not being the case as we’re talking about one of the biggest companies in the world, but there’s always a chance.”
What are the companies saying?
Facebook issued an apology for the outage.
Facebook Engineering said in a statement on Twitter: “To the huge community of people and businesses around the world who depend on us: we’re sorry.
“We’ve been working hard to restore access to our apps and services and are happy to report they are coming back online now. Thank you for bearing with us.”
The official Twitter account humorously tweeted: “Hello literally everyone.”