Identity and Access Management Risks
As Slack becomes a central hub for workplace communication, managing identities grows more complex—especially with its expanding use among employees and external collaborators. Slack Connect allows organizations to collaborate with external partners, contractors, and vendors, but without proper management, these external users may retain unnecessary access to internal channels, messages, and files long after their collaboration ends. Ensuring that guest accounts and third-party users have only authorized access—and are promptly offboarded when no longer needed—is crucial for maintaining security. Additionally, local Slack accounts that bypass corporate Identity Provider (IdP) controls can result in weak authentication, such as a lack of MFA enforcement. It is important that security teams have visibility into these unmanaged accounts, in order to enforce security policies and prevent unauthorized access.

Misconfigurations and Configuration Drift
Misconfigured Slack settings can leave organizations vulnerable to security breaches. Policies related to session duration limits, email domain restrictions, and external collaboration permissions are just a few examples of configurations that must be carefully managed to prevent unauthorized access and data leakage. Furthermore, configuration drift—where security settings gradually deviate from best practices—can weaken defenses over time.

Securing Slack App Integrations
Slack’s integration ecosystem is powerful, but third-party Slack Apps can introduce significant security risks if not properly managed. Many integrations installed by Slack Administrators have elevated privileges, allowing extensive access to channels, messages, files, and user data. Attackers could exploit these integrations to gain unauthorized access, manipulate data, or perform other malicious activities. Over time, dormant or high-risk integrations accumulate, expanding the organization’s attack surface.

Preventing Data Exposure and Oversharing
Slack often contains troves of sensitive data posted in channels, direct messages, and file shares, which can include customer or employee PII, product roadmap plans, and confidential business strategies. Without proper controls, information can be inadvertently exposed in public channels or shared with unauthorized users. Additionally, Slack Connect settings can introduce external access risks if not properly configured.

Lateral Movement Risks in Slack
A compromised Slack account can serve as a launchpad for attackers to move laterally within an organization. Attackers can send malicious messages, spear phishing attempts, or social engineering campaigns to other users within the Slack workspace, exploiting internal trust. One They may also gain access to private channels where sensitive information is shared, potentially harvesting credentials or gathering intelligence for further attacks. In one case, attackers infiltrated Electronic Arts (EA) by using stolen cookies to access Slack, where they tricked IT support into providing an MFA token—ultimately allowing them to breach EA’s network and steal game source code.