Slack security: how secure are Slack workspaces

Anton P. | January 18, 2023

Faulty Slack security could ruin your experience on this collaboration hub. You might already know that employers can read private Slack messages exchanged between co-workers. However, Slack security concerns go beyond that after digging deeper into its data protection practices.

So, see what security and privacy protections Slack offers and what elements depend on decisions from individual workplaces. 

Slack security depends on workspace settings, plans, and how users react to messages from teammates. Follow simple rules to use Slack safely.

What is Slack? 

Slack is an attractive and user-friendly platform for companies to unite employees. While its original purpose was to support organizational communications, it also became a community platform. 

  • Slack has a free plan with limited features, but premium plans offer more, like enterprise-grade security and advanced identity management. 
  • The Slack free version does support data encryption at rest and in transit, plus two-factor authentication. 
  • However, only premium plans have SAML-based single sign-on (SSO) and OAuth with Google. 
  • Also, the support for HIPAA compliance only comes with the most expensive premium plan. 

Slack security: what you should know 

Slack is a respectable company that faces many challenges, from vulnerabilities to human error. The popularity of Slack could make it a more lucrative target for criminals. 

In 2015, Slack suffered a database hack, exposing encrypted and salted passwords of Slack accounts. While you might continue using Slack due to its productivity benefits, it is essential to recognize the potential risks. 

  1. Vulnerabilities in Slack security 

Slack security teams are responsible for keeping software compliant and safe to use. However, many services battle bugs and flaws that could either interrupt workflows or assist as exploits for hackers. 

Previous Slack security issues related to threats like stolen employee tokens and execution of arbitrary code within Slack. 

User solution 

Slack users do not have control over how quickly security research teams resolve issues. However, it is crucial to ensure timely updates for Slack as they might fix critical bugs. Also, enable VPN when working to ensure that all data exchanges happen safely.

  1. Picking appropriate Slack plans 

Slack security promises data protection at rest and in transit for all users. However, only particular plans might work depending on what information teams share. 

For instance, Slack Enterprise Key Management enables companies to use unique keys for encrypting messages and files. Furthermore, only the Enterprise Grid plan offers support for HIPAA compliance. 

User solution

Companies interested in using Slack can contact Slack’s sales team. They should help you choose an appropriate plan for securely and conveniently managing information. 

  1. Reassuring invite-only compliance 

You must receive invitations to join Slack workspaces. However, it also relates to ensuring that only intended slackers can join particular channels. So, Slack security directly depends on limiting access to your workspace. 

User solution 

These tips can help boost Slack security and guarantee that the right teams have access to information: 

  • Admins should require approval for invitations to join workspaces. 
  • It is possible to set that only particular email domains can join your workspace.
  • Slack Connect allows you to accept people outside your company safely. 
  • Consider setting up guest accounts for employees that do not need permanent or full access. 
  1. Onboarding and termination procedures 

Another Slack security issue might be how companies deal with onboarding and termination. For instance, adding external members to a workspace is a delicate matter. It is crucial to guarantee that they can only gain access to data within their scope. 

User solution

One of the key elements of secure onboarding and offboarding is smooth communication between HR and Slack admins. Former employees should not retain access after leaving. 

Another crucial thing is regularly reviewing whether external members should get removed from Slack workspaces. 

  1. Third-party app integrations with Slack 

Third-party integrations with Slack facilitate a seamless task flow without leaving your workspace. However, experts associate certain risks, particularly after integrations have already caused issues. 

In 2016, an 18F unit from the General Services Administration exposed confidential data due to Slack integration with Google Drive

User solution 

Companies should establish clear policies regarding app integration or keep them at a minimum. It is also possible to ban specific Slack app integrations. 

  1. Problems with Slack open communities 

Slack security also relates to what information teams share. Slack workspaces likely have many channels, many of them unrelated to work. 

Overall, it is crucial to guarantee that exchanged information is safe from offensive comments or malicious content. 

User solution

A suspicious activity like sharing confidential information on the wrong channel might be accidental. However, there are some things you should avoid via Slack messages for security and general courtesy: 

  • If you try to inform your team about dangerous links, clearly state that others should not click on them.
  • Never share clients’ personal information like names, passwords, or email addresses. 
  • Do not share passwords on Slack or other highly confidential information. 
  • The general rule of thumb is that information hackers could exploit does not belong on Slack. 
  • Using various security tools and techniques like two-factor authentication and regular reviews is best.

What information Slack collects about active users? 

According to Slack privacy policy, it can collect an array of user information: 

  • It gathers account and workspace details like email addresses, phone numbers, and billing information. 
  • Slack logs which channels, workspaces, content, and links you interact with or view. 
  • It gathers what website you visited before opening it, IP addresses, dates of the visits, and browser configuration. 
  • Slack also gets details about your approximate location, likely through IP addresses or third-party integrations. 
  • Slack also retrieves video and audio metadata generated through calls or Slack Huddles.
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Anton P.

Anton P.

Former chef and the head of Atlas VPN blog team. He's an experienced cybersecurity expert with a background of technical content writing.



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