CVE-2023-32694 in Adyen Plugin
Summary
by MITRE • 05/25/2023
Saleor Core is a composable, headless commerce API. Saleor's `validate_hmac_signature` function is vulnerable to timing attacks. Malicious users could abuse this vulnerability on Saleor deployments having the Adyen plugin enabled in order to determine the secret key and forge fake events, this could affect the database integrity such as marking an order as paid when it is not. This issue has been patched in versions 3.7.68, 3.8.40, 3.9.49, 3.10.36, 3.11.35, 3.12.25, and 3.13.16.
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Analysis
by VulDB Data Team • 06/17/2023
The vulnerability identified as CVE-2023-32694 affects Saleor Core, a composable headless commerce API that serves as the foundation for modern e-commerce implementations. This issue specifically targets the `validate_hmac_signature` function within Saleor's codebase, which is responsible for authenticating webhook events received from payment providers such as Adyen. The flaw manifests as a timing attack vulnerability that exploits the predictable execution time differences in cryptographic operations, allowing malicious actors to infer sensitive information through careful measurement of response times.
The technical implementation of this vulnerability stems from the function's non-constant time comparison mechanism used during HMAC signature validation. When comparing cryptographic signatures, proper implementations must use constant-time algorithms to prevent attackers from determining the correct values through timing variations. This weakness creates an avenue for attackers to perform side-channel attacks where they can systematically test potential secret key values and observe the response timing differences to gradually reconstruct the actual secret key. The vulnerability is particularly dangerous because it specifically impacts deployments utilizing the Adyen plugin, which processes payment notifications and webhook events that require authentication.
The operational impact of this vulnerability extends beyond simple authentication bypass to potentially compromise the entire commerce system's integrity. An attacker who successfully determines the secret key could forge legitimate webhook events from Adyen, manipulating order statuses in the database to mark unpaid orders as paid. This could result in significant financial losses, inventory discrepancies, and undermine the trust in the entire payment processing system. The database integrity is at risk as maliciously forged events could alter order processing workflows, potentially allowing unauthorized access to payment information and enabling fraudulent transactions. This vulnerability directly aligns with CWE-327, which addresses the use of insecure cryptographic algorithms, and represents a classic example of how timing attacks can compromise security through information leakage.
Mitigation strategies for this vulnerability require immediate deployment of patched versions 3.7.68, 3.8.40, 3.9.49, 3.10.36, 3.11.35, 3.12.25, and 3.13.16 as recommended by the vendor. Organizations should also implement monitoring for unusual webhook activity patterns and consider additional authentication layers for critical payment processing endpoints. The fix addresses the timing attack surface by implementing constant-time comparison algorithms in the HMAC validation process, preventing attackers from extracting secret key information through timing analysis. Security teams should conduct thorough audits of their payment integration points and verify that all webhook endpoints utilize secure cryptographic comparison mechanisms. This vulnerability demonstrates the importance of proper cryptographic implementation practices and aligns with ATT&CK technique T1211, which covers the use of timing attacks to extract information from cryptographic systems. Organizations should also consider implementing rate limiting and additional validation checks for webhook endpoints to further reduce the attack surface and prevent exploitation of similar timing-based vulnerabilities.