Slack leaked hashed passwords from its servers for years
(2022/08/08)
- Reference: 1659959108
- News link: https://www.theregister.co.uk/2022/08/08/slack_passwords/
- Source link:
Did Slack send you a password reset link last week? The company has admitted to accidentally exposing the hashed passwords of workspace users.
The [1]issue occurred when a user created or revoked a shared invitation link for their workspace. The good news is that the password wasn't plaintext, and it wasn't visible in any Slack clients. The bad news is that it could be picked up by monitoring encrypted traffic from Slack's servers, and it appears that all users who created or revoked those links between April 17, 2017, and July 17, 2022, are affected.
Slack said only 0.5 percent of users were affected, which doesn't sound too terrible until you consider how many Slack users are out there. While getting a definitive user figure for any chat platform is tricky and varies depending on what measure the vendor is using, it is safe to assume Slack has 10 million or more daily active users, meaning that at least 50,000 could have been affected. We asked the company to confirm this, and will update if there is a response.
[2]
Slack lays claim to over 169,000 paid customers and says "millions of people around the world use Slack to connect their teams."
[3]Slack to increase prices for Pro customers
[4]60 million in the Matrix as users seek decentralized messaging
[5]Slack-for-engineers Mattermost on open source and data sovereignty
[6]Email out, Slack and Teams in for business communications
The company was informed of the issue by an independent security researcher on July 17, and swiftly fixed the issue before assessing the scale of the impact. "We have no reason to believe that anyone was able to obtain plaintext passwords because of this issue," it insisted, but has still reset the passwords of affected users regardless.
It also recommends the inevitable move to two-factor authentication and the use of unique passwords for every service in use.
[7]
The problem is that while the passwords were hashed and salted, and Slack noted that "it is practically infeasible for a password to be derived from the hash," extracting a password is possible (the key word is "practically"). Miscreants are well versed in brute-force methods and it has been possible to harvest those passwords for years.
It would therefore also be a good idea to check out the access logs for one's account, just in case, as well as perform the reset as recommended by Slack. ®
Get our [8]Tech Resources
[1] https://slack.com/intl/en-gb/blog/news/notice-about-slack-password-resets
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_security/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YvEzIme5kEkuz8Hsq19OPAAAABQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://www.theregister.com/2022/07/19/slack_price_rise/
[4] https://www.theregister.com/2022/07/15/matrix_grows/
[5] https://www.theregister.com/2022/05/26/mattermost/
[6] https://www.theregister.com/2022/05/10/business_comms_swzd/
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_security/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YvEzIme5kEkuz8Hsq19OPAAAABQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[8] https://whitepapers.theregister.com/
The [1]issue occurred when a user created or revoked a shared invitation link for their workspace. The good news is that the password wasn't plaintext, and it wasn't visible in any Slack clients. The bad news is that it could be picked up by monitoring encrypted traffic from Slack's servers, and it appears that all users who created or revoked those links between April 17, 2017, and July 17, 2022, are affected.
Slack said only 0.5 percent of users were affected, which doesn't sound too terrible until you consider how many Slack users are out there. While getting a definitive user figure for any chat platform is tricky and varies depending on what measure the vendor is using, it is safe to assume Slack has 10 million or more daily active users, meaning that at least 50,000 could have been affected. We asked the company to confirm this, and will update if there is a response.
[2]
Slack lays claim to over 169,000 paid customers and says "millions of people around the world use Slack to connect their teams."
[3]Slack to increase prices for Pro customers
[4]60 million in the Matrix as users seek decentralized messaging
[5]Slack-for-engineers Mattermost on open source and data sovereignty
[6]Email out, Slack and Teams in for business communications
The company was informed of the issue by an independent security researcher on July 17, and swiftly fixed the issue before assessing the scale of the impact. "We have no reason to believe that anyone was able to obtain plaintext passwords because of this issue," it insisted, but has still reset the passwords of affected users regardless.
It also recommends the inevitable move to two-factor authentication and the use of unique passwords for every service in use.
[7]
The problem is that while the passwords were hashed and salted, and Slack noted that "it is practically infeasible for a password to be derived from the hash," extracting a password is possible (the key word is "practically"). Miscreants are well versed in brute-force methods and it has been possible to harvest those passwords for years.
It would therefore also be a good idea to check out the access logs for one's account, just in case, as well as perform the reset as recommended by Slack. ®
Get our [8]Tech Resources
[1] https://slack.com/intl/en-gb/blog/news/notice-about-slack-password-resets
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_security/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YvEzIme5kEkuz8Hsq19OPAAAABQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://www.theregister.com/2022/07/19/slack_price_rise/
[4] https://www.theregister.com/2022/07/15/matrix_grows/
[5] https://www.theregister.com/2022/05/26/mattermost/
[6] https://www.theregister.com/2022/05/10/business_comms_swzd/
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_security/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YvEzIme5kEkuz8Hsq19OPAAAABQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[8] https://whitepapers.theregister.com/
Only .5% of users affected.
OldCrow 1975
Where else have I heard that number before.
Oh yes Twitter pertaining to bots. I wonder if there is a relationship between the two.
Re: Only .5% of users affected.
Ben Tasker
That was 5 percent, this number is a tenth of that
Anonymous Coward
A spokesperson commented that "the problem was a result in a simple misunderstanding of the role of the slack security team"
Dónde está Paris?
Locky
Slack, a tool promoted by Marketing departments for years because "it bypasses all those pesky IT rules and just works", is insecure?
I am shocked
Re: Dónde está Paris?
steviebuk
Until they realised they had to pay for parts of it and all that chat history? Yeah you have to pay for that as well. So where I was it got abandoned :)
Pirate Dave
"...it is safe to assume Slack has 10 million or more daily active users..."
"Slack lays claim to over 169,000 paid customers..."
I gotta think that at some point, the paying customers are going to get tired of subsidizing the Slack slackers...
Slack lays claim to over 169,000 paid customers and says "millions of people around the world use Slack to connect their teams."
No Teams, is Microsoft's rival...