CVE-2020-37168 -- CVSS 9.8 Vulnerability Briefing

CVE-2020-37168 | CVSS 9.8 (Critical) | Exploit: No known exploit

What Is It

CVE-2020-37168 is a weak cryptographic implementation vulnerability in Ecommerce Systempay version 1.0, affecting the payment signature generation mechanism that relies on a brute-forceable 16-character production secret key.

Technical Detail

The flaw stems from the use of an insufficiently complex secret key for generating payment transaction signatures, where the key space is small enough to be exhausted through brute force attack. An attacker who can observe legitimate signed payment requests can collect signature samples and systematically attempt key recovery offline or against the live system. Successful key recovery allows the attacker to forge valid payment signatures, enabling transaction manipulation, fraudulent payment approvals, or bypass of payment integrity controls.

Exploitation Status

No known exploit code has been publicly documented for this vulnerability, and it is not listed in the CISA Known Exploited Vulnerabilities catalog. There is no confirmed evidence of active exploitation in the wild at this time. The theoretical attack requires access to signed transaction data, which may limit opportunistic exploitation, but the brute-force approach is technically straightforward given the constrained key space.

Who Is Targeting This

No specific threat actor attribution at this time. However, vulnerabilities affecting payment signature mechanisms are historically of interest to financially motivated actors targeting e-commerce platforms for fraud and transaction manipulation.

What To Do

Organizations running Ecommerce Systempay 1.0 should immediately replace the production secret key with a cryptographically strong key of sufficient length and entropy, following current standards such as NIST SP 800-57. If a patched version of Systempay is available from the vendor, it should be applied as a priority given the CVSS score of 9.8. If no patch exists, consider disabling the affected payment integration until a remediated version is available or a compensating control such as IP allowlisting for payment callbacks can be enforced. Review transaction logs for anomalous signature patterns that could indicate prior key recovery attempts.