Cryptography and SSL/TLS Toolkit

Security Policy

Reporting security issues

If you wish to report a possible security issue in OpenSSL please notify us.

Issue triage

Notifications are received by the OMC and OTC. We engage resources within OpenSSL to start the investigation and prioritisation. We may work in private with individuals who are not on the OMC or OTC as well as other organisations and our employers where we believe this can help with the issue investigation, resolution, or testing.

Threat Model

Certain threats are currently considered outside of the scope of the OpenSSL threat model. Accordingly, we do not consider OpenSSL secure against the following classes of attacks:

  • same physical system side channel
  • CPU/hardware flaws
  • physical fault injection
  • physical observation side channels (e.g. power consumption, EM emissions, etc)

Mitigations for security issues outside of our threat scope may still be addressed, however we do not class these as OpenSSL vulnerabilities and will therefore not issue CVEs for any mitigations to address these issues.

We are working towards making the same physical system side channel attacks very hard.

Prior to the threat model being included in this policy, CVEs were sometimes issued for these classes of attacks. The existence of a previous CVE does not override this policy going forward.

Issue severity

We will determine the risk of each issue, taking into account our experience dealing with past issues, versions affected, common defaults, and use cases. We use the following severity categories:

  • CRITICAL Severity. This affects common configurations and which are also likely to be exploitable. Examples include significant disclosure of the contents of server memory (potentially revealing user details), vulnerabilities which can be easily exploited remotely to compromise server private keys or where remote code execution is considered likely in common situations. These issues will be kept private and will trigger a new release of all supported versions. We will attempt to address these as soon as possible.
  • HIGH Severity. This includes issues that are of a lower risk than critical, perhaps due to affecting less common configurations, or which are less likely to be exploitable. These issues will be kept private and will trigger a new release of all supported versions. We will attempt to keep the time these issues are private to a minimum; our aim would be no longer than a month where this is something under our control.
  • MODERATE Severity. This includes issues like crashes in client applications, flaws in protocols that are less commonly used (such as DTLS), and local flaws. These will in general be kept private until the next release, and that release will be scheduled so that it can roll up several such flaws at one time.
  • LOW Severity. This includes issues such as those that only affect the openssl command line utility, or unlikely configurations. These will in general be fixed immediately in latest development versions, and may be backported to older versions that are still getting updates. We will update the vulnerabilities page and note the issue CVE in the changelog and commit message, but they may not trigger new releases.

Prenotification policy

  • Where we are planning an update that fixes security issues we will notify the openssl-announce list and update the OpenSSL website to give our scheduled update release date and time and the severity of issues being fixed by the update. No further information about the issues will be given.
  • Where we are planning an update that include CRITICAL, HIGH, or MODERATE severity issues we will also prenotify certain organisations with more details and patches.
    • The organisations we prenotify include those that produce a general purpose OS that uses OpenSSL as included on this list of Operating System distribution security contacts.
    • We also include other open source projects that are derived from OpenSSL which have a significant user base and a reciprocal arrangement.
    • We may also include other organisations that are not listed but would otherwise qualify for list membership.
    • We may also include organisations with which we have a commercial relationship.
    • We may withdraw notifying certain organisations from future prenotifications if they leak issues before they are public or over time do not add value.

Note: researchers or intermediaries who notify us of issues may have their own prenotification policy in addition to ours.


The policy above is guided by our security principles:

  • It’s in the best interests of the Internet as a whole to get fixes for OpenSSL security issues out quickly. OpenSSL embargoes should be measured in days and weeks, not months or years.
  • Many sites affected by OpenSSL issues will be running a version of OpenSSL they got from some vendor (and likely bundled with an operating system). The most effective way for these sites to get protected is to get an updated version from that vendor.