Envoy has an evolving policy on external dependencies, tracked at envoyproxy#10471. This will become stricter over time, below we detail the policy as it currently applies.
The list of external dependencies in Envoy with their current version is available at https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/security/external_deps
In general, all external dependencies for the Envoy proxy binary build and test should be declared in either bazel/repository_locations.bzl or api/bazel/repository_locations.bzl, unless listed under policy exceptions.
An example entry for the nghttp2
dependency is:
com_github_nghttp2_nghttp2 = dict(
project_name = "Nghttp2",
project_url = "https://nghttp2.org",
version = "1.41.0",
sha256 = "eacc6f0f8543583ecd659faf0a3f906ed03826f1d4157b536b4b385fe47c5bb8",
strip_prefix = "nghttp2-{version}",
urls = ["https://github.com/nghttp2/nghttp2/releases/download/v{version}/nghttp2-{version}.tar.gz"],
use_category = ["dataplane"],
cpe = "cpe:2.3:a:nghttp2:nghttp2:*",
),
Dependency declarations must:
- Provide a meaningful project name and URL.
- State the version in the
version
field. String interpolation should be used instrip_prefix
andurls
to reference the version. If you need to reference versionX.Y.Z
asX_Y_Z
, this may appear in a string as{underscore_version}
, similarly forX-Y-Z
you can use{dash_version}
. - Versions should prefer release versions over master branch GitHub SHA tarballs. A comment is necessary if the latter is used. This comment should contain the reason that a non-release version is being used and the YYYY-MM-DD when the last update was performed.
- Provide accurate entries for
use_category
. Please think carefully about whether there are data or control plane implications of the dependency. - CPEs are compulsory for all dependencies that are not purely build/test.
CPEs provide metadata that allow us
to correlate with related CVEs in dashboards and other tooling, and also provide a machine
consumable join key. You can consult the latest CPE
dictionary to find a CPE for a dependency.
"N/A"
should only be used if no CPE for the project is available in the CPE database. CPEs should be versionless with a:*
suffix, since the version can be computed fromversion
.
When build or test code references Python modules, they should be imported via pip3_import
in
bazel/repositories_extra.bzl. Python modules should not be listed in
repository_locations.bzl
entries. requirements.txt
files for Python dependencies must pin to
exact versions, e.g. PyYAML==5.3.1
and ideally also include a SHA256
checksum.
Pure developer tooling and documentation builds may reference Python via standalone
requirements.txt
, following the above policy.
-
Any new dependency on the Envoy data or control plane that impacts Envoy core (i.e. is not specific to a single non-core extension) must be cleared with the Envoy security team, please file an issue and tag @envoyproxy/security-team. While policy is still evolving, criteria that will be used in evaluation include:
- Does the project have release versions? How often do releases happen?
- Does the project have a security vulnerability disclosure process and contact details?
- Does the project have effective governance, e.g. multiple maintainers, a governance policy?
- Does the project have a code review culture? Are patches reviewed by independent maintainers prior to merge?
- Does the project enable mandatory GitHub 2FA for contributors?
- Does the project have evidence of high test coverage, fuzzing, static analysis (e.g. CodeQL), etc.?
-
Dependencies for extensions that are tagged as
robust_to_untrusted_downstream
orrobust_to_untrusted_downstream_and_upstream
should be sensitive to the same set of concerns as the core data plane.
We rely on community volunteers to help track the latest versions of dependencies. On a best effort basis:
-
Core Envoy dependencies will be updated by the Envoy maintainers/security team.
-
Extension CODEOWNERS should update extension specific dependencies.
Where possible, we prefer the latest release version for external dependencies, rather than master branch GitHub SHA tarballs.
The following dependencies are exempt from the policy:
-
Any developer-only facing tooling or the documentation build.
-
Transitive build time dependencies, e.g. Go projects vendored into protoc-gen-validate.