Is Slack secure? Exploring the major concerns and the best alternative

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With over 10 million daily active users, Slack's popularity also makes it a prime target for cybercriminals. This increases the risk of data breaches, raising a vital question for enterprises seeking safe collaboration: Is Slack secure?

As per Mimecast, 1 in 166 messages sent on Slack contains confidential information, creating opportunities for unauthorized access, phishing, or data leaks.

In July 2024, a noteworthy incident also took place, which questioned its integrity.

A group named "NullBulge" claimed to have leaked 1.1 terabytes of Disney's internal Slack messages, including unreleased projects, code, and login credentials.

Moreover, Slack's reliance on third-party integrations and APIs, while boosting functionality, can also expand its attack surface if not properly secured.

This article evaluates Slack's vulnerabilities and suggests Slack alternatives for better data security. Let us address the key question: Is Slack secure?

Overview of Slack's security features

Given Slack's widespread use as a business communication and collaboration platform, it's important to understand its security features:

Data encryption

Slack does encrypt data in transit and at rest using AES-256 encryption. This protects conversations from external interception. However, it lacks end-to-end encryption at present.

Compliance standards

The tool complies with several key data security standards, including SOC 2, SOC 3, ISO 27001, and GDPR.

Enterprise key management (EKM)

Slack's Enterprise Key Management (EKM) enhances security by enabling organizations to use their encryption keys stored in Amazon's Key Management Service (AWS KMS).

Two-factor authentication (2FA)

Two-factor authentication (2FA) adds an extra layer of security to Slack user accounts.

Single sign-on (SSO)

Single sign-on (SSO) in Slack provides centralized access management for enterprises. This feature simplifies the login process by allowing users to access Slack.

Is Slack secure? Some concerns and notable incidents

After reviewing Slack's security features, it's important to examine its vulnerabilities. Because for many privacy-conscious organizations, the question persists: Is Slack secure?

To note, recently, Slack has faced criticism for using user data to train its AI models without explicit consent, automatically opting users into data collection practices.

This has raised concerns about transparency, as Slack's privacy statements seem contradictory. Plus, the opt-out process is complicated, requiring a request from an organization's admin, making it difficult for individual users to control their data.

Here are the other significant security incidents associated with Slack:

2022 GitHub breach

In December 2022, Slack's private code repositories on GitHub were compromised using stolen employee tokens.

This was found when suspicious activity was found on their GitHub account on December 29, 2022. Although no customer data was affected, the breach indicates the vulnerabilities that could be exploited through brute force attacks, prompting Slack to invalidate the compromised tokens and enhance security measures to prevent future incidents.

2024 bot vulnerability

In August 2024, a vulnerability in Slack's AI integration was exploited to exfiltrate data from private channels via indirect prompt injection.

Attackers manipulated AI-generated responses to include sensitive information from private conversations. This exploit leveraged the AI's ability to access and process data across channels, bypassing traditional access controls.

Soon, Slack responded by enhancing AI monitoring and implementing stricter verification processes for AI-generated content to prevent unauthorized data access.

Uber incident (September 2022)

In September 2022, a hacker infiltrated Uber's systems by sending a message to employees via Slack, claiming to be a hacker.

The breach was facilitated by malware on a contractor's phone, which allowed the attacker to execute a multi-factor fatigue attack. This incident not only compromised Slack but also affected other systems like Google Workspace and AWS.

Rockstar Games breach (2022)

In 2022, hackers used social engineering to compromise a Rockstar Games employee's Slack account.

Just days after the Uber incident, the same hacker targeted Rockstar Games' Slack instance, exfiltrating 90 videos of unreleased game footage for Grand Theft Auto VI.

The incident highlighted the vulnerabilities associated with social engineering attacks and the need for enhanced security measures, such as Role-Based Access Control (RBAC), to mitigate these risks.

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Is Slack secure? 5 Some potential risks users must know

Now, to answer ‘Is Slack secure?’ let us focus on the major risks of this messaging tool and the solutions:

Third-party integrations

Risk: Third-party integrations can inadvertently expose sensitive information. For example, a 2016 incident involved employees sharing Google Drive documents through Slack, leading to significant data exposure due to improper authentication protocols.

So, over 2,600 apps and bots connected to Slack may pose some risks.

For example, around 43% of third-party apps in the Slack App Store can read messages within chats.

This means sensitive information within these channels can be accessed if any third-party apps are compromised.

Solution: some text
- Restrict app usage to vetted and necessary tools.
- Conduct regular security assessments of third-party integrations.
- Limit permissions to only what is necessary for functionality.

User misconfiguration

Risk: Poorly set permissions can lead to data leaks. For example, if users are given access to channels that contain sensitive information without proper oversight, they may inadvertently expose this data to unauthorized individuals.

A study by Forbes indicated that 74% of data breaches result from misconfigured permissions or inadequate access controls.

Solution: some text
- Regular audits of user roles and channel settings.
- Implement strict access controls and ensure that permissions are appropriately set based on the principle of least privilege.

Lack of end-to-end encryption

Limitation: Slack does not provide true end-to-end encryption for messages.

While messages are encrypted in transit and at rest using TLS and AES-256 encryption, they are accessible on Slack's servers.

Impact: This means that Slack can potentially access decrypted messages if its servers are compromised—leading many organizations to question: Is Slack secure? For example, a Slack data breach could expose private messages to hackers.

Human error

Risk: Employees accidentally share sensitive information in public channels.

According to Veritas, 71% of employees have accidentally shared confidential information through collaboration tools.

Solution: some text
- Train employees on secure collaboration practices.
- Regularly educate staff on the importance of verifying the correct channels before sharing sensitive information.
- Encourage the use of private channels for confidential discussions.

Data leakage

Risk: Conversations on Slack are stored indefinitely unless manually deleted. This can lead to the accumulation of sensitive data over time, increasing the risk of exposure in the event of a breach.

80% of Fortune 100 companies use Slack, which means a vast amount of sensitive data is continuously exchanged and stored.

Solution: some text
- Implement data retention policies to delete old messages and files automatically.
- Regularly review and purge unnecessary data to minimize the amount of sensitive information stored on the platform.

Why Rocket.Chat is a secure alternative to Slack

Rocket.Chat is trusted by over 12 million users worldwide and has been adopted by more than 800,000 organizations.

With features like true end-to-end encryption, on-premise hosting options, and a proven track record in performing in high-security environments including military, government, education, and healthcare—Rocket.Chat stands out as a suitable Slack alternative.

Here are some of its key features:

True end-to-end encryption

Rocket.Chat provides true end-to-end encryption (E2EE) for messages, ensuring that only the intended recipients can decrypt and read the messages.

For example, organizations like the City of Cologne have adopted the tool for its strong encryption capabilities.

Open-source architecture

Unlike Slack, Rocket.Chat is open-source, allowing organizations full control over their data and the platform's security configuration. This transparency enables businesses to audit the code, customize security settings, white label the chat app as needed, and ensure no hidden vulnerabilities.

For instance, Audi chose the tool due to its open-source nature, which allowed them to meet stringent data privacy requirements.

On-premise hosting options

Organizations can host the platform on their servers, adding an extra layer of security by keeping data within their infrastructure. This is particularly beneficial for industries with strict data sovereignty laws.

For example, the U.S. Department of Defense uses Rocket.Chat for its Platform One DevSecOps initiative.

Customizable features

It allows deep customization to meet unique business security needs. Organizations can modify the platform's codebase, create custom themes, and integrate specific functionalities.

For instance, a healthcare provider customized the tool to comply with HIPAA regulations.

Proven track record in high-security environments

Government agencies and enterprises requiring advanced security measures trust the platform. It is ISO 27001 certified and SOC 2 compliant, demonstrating its capability to handle sensitive data securely.

Cost efficiency for enhanced security

Rocket.Chat offers strong security features at a fraction of the cost of Slack Enterprise Grid. This makes it an attractive option for organizations looking to enhance their security without incurring high costs, especially for those wondering: is Slack secure?

End note

Although Slack provides strong security features, its lack of end-to-end encryption and reliance on third-party integrations often makes organizations ask: is Slack secure?

Rocket.Chat addresses these concerns with advanced security, including true end-to-end encryption, customizable configurations, and full data ownership. Its open-source nature allows businesses to audit and tailor the collaboration platform to meet specific security needs.

Take control of your team's security—connect with our teams and try Rocket.Chat today!