Zapier exploit chain shows how known anti-patterns compose into critical risk

Key Points:

• A five-stage exploit chain was discovered in Zapier, allowing unauthorized write access to public and internal SDK packages due to known anti-patterns across multiple systems.
• The impact includes potential execution of attacker-controlled JavaScript in authenticated sessions, although no evidence of exploitation has been found in the wild. The vulnerability was contained within the permissions of the compromised AWS Lambda role.
• Recommended actions include reviewing and tightening IAM roles and permissions, as well as conducting a thorough forensic analysis to ensure no unauthorized access occurred during the exposure window.

Technical Details: The exploit leveraged a combination of vulnerabilities in AWS Lambda, ECR, and NPM token management, allowing researchers to recover sensitive tokens without proper safeguards. The NPM token had write permissions and could have allowed malicious package uploads.

MITRE ATT&CK Techniques:

• T1078 - Valid Accounts (Defense Evasion)
• T1203 - Exploitation for Client Execution (Execution)
• T1071.001 - Application Layer Protocol: Web Protocols (Command and Control)

IOCs Mentioned: None mentioned