Heym before 0.0.53 fails to verify Slack request signatures when trigger nodes lack credential IDs or have empty signing secrets. Remote unauthenticated attackers can send forged Slack events to known webhook URLs to trigger workflows with the owner's credentials.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
heymrun:heym
References 3
https://github.com/heymrun/heym/security/advisories/GHSA-pm6h-x3h5-j38h
GitHub Security Advisory (GHSA-pm6h-x3h5-j38h)
https://github.com/heymrun/heym/commit/341d1012367cd74f85c617e1c98dd49e3fcb5e83
Patch Commit
https://www.vulncheck.com/advisories/heym-before-0.0.53-slack-webhook-signature…
VulnCheck Advisory: Heym before 0.0.53 Slack Webhook Signature Verification Bypass