Responsible Disclosure

At Greenhost, we consider the security of our systems a top priority. But no matter how much effort we put into system security, there can still be vulnerabilities present.

If you discover a vulnerability, we would like to know about it, so we can take steps to address it as quickly as possible. We would like to ask you to help us better protect our clients and our systems. This is also called a "Coordinated Vulnerability Disclosure Policy".

Please do the following:

  • E-mail your findings to, if possible encrypt your findings using our PGP key below to prevent this critical information from falling into the wrong hands.
  • Do not take advantage of the vulnerability or problem you have discovered, for example by downloading more data than necessary to demonstrate the vulnerability or deleting or modifying other people's data.
  • Do not reveal the problem to others until it has been resolved.
  • Do not use attacks on physical security, social engineering, distributed denial of service, spam or applications of third parties.
  • Do provide sufficient information to reproduce the problem, so we will be able to resolve it as quickly as possible. Usually, the IP address or the URL of the affected system and a description of the vulnerability will be sufficient, but complex vulnerabilities may require further explanation.

What we promise:

  • We will respond to your valid report within five business days with our evaluation of the report and an expected resolution date. If you have followed the instructions above, we will not take any legal action against you in regard to the report.
  • We will handle your report with strict confidentiality, and not pass on your personal details to third parties without your permission.
  • We will keep you informed of the progress towards resolving the problem.
  • In the public information concerning the problem reported, we will give your name as the discoverer of the problem in our hall of fame (unless you desire otherwise)
  • As a token of our gratitude for your assistance, new and accepted security reports will qualify for a reward. The amount of the reward will be determined based on the severity of the vulnerability and the quality of the report.
  • We strive to resolve all problems as quickly as possible, and we would like to play an active role in the ultimate publication on the problem after it is resolved.


Accepted reports qualify for a reward if you have adhered to the guidelines in this policy. Please note: reward decisions are up to the discretion of Greenhost. At this point we have chosen not yet to disclose our reward tiers. If you want to qualify for a reward make sure you read the following sections on eligibility.

Reports that do not qualify for a Reward

  • Security advice or best practices; As a rule of thumb, everything that can be diagnosed with a public online tester falls in this category.
  • Configuration disclosures and path disclosures are typically not considered vulnerabilities.
    • If still reporting one of these issues, please include proof of credential leakage, or demonstrate an attack with the leaked information.
  • Tampering: Temporary modification of data in a specific scenario that does not persist, requiring user interaction to be exploitable.
  • Security vulnerabilities that are already reported or currently in a disclosure process (duplicate).

Out of scope (not accepted)

  • Reports on any system of a customer on a Greenhost network. If you submit a report to a system that belongs to a customer, we consider them a party in the report and share any findings if deemed appropriate by us.
  • Using Social engineering (e.g. phishing, vishing, smishing) is prohibited.
  • Vulnerability in another project/software that Greenhost depends on. If you think you discovered a vulnerability in another project/software, and that project has their own vulnerability reporting and disclosure process, please report it directly there.

Known disclosures

  • The following are part of a roadmap, and we are no longer soliciting reports on this matter:
    • E-mail policies such as SPF, DKIM and DMARC.
    • HTTP headers policies such as X-Frame-Options, HSTS, Host headers injections.
  • Past disclosed reports can be seen in our hall of fame.


Contact email address:

GPG Fingerprint: 207C FAB6 ACD9 EF3E C5B3 C8FA F965 32D2 7CF8 368E

Full GPG public key

Parts of this policy adapted from CC-BY Floor Terra