Remote code execution vulnerability in dependabot-common
and dependabot-go_modules
when a source branch name contains malicious injectable bash code.
For example, if Dependabot is configured to use the following source branch name: "/$({curl,127.0.0.1})"
, Dependabot will make a HTTP request to the following URL: 127.0.0.1 when cloning the source repository.
When Dependabot is configured to clone the source repository during an update, Dependabot runs a shell command to git clone the repository:
git clone --no-tags --no-recurse-submodules --depth=1 --branch=<BRANCH> --single-branch <GITHUB_REPO_URL> repo/contents/path
Dependabot will always clone the source repository for go_modules
during the file fetching step and can be configured to clone the repository for other package managers using the FileFetcher
class from dependabot-common
.
source = Dependabot::Source.new(
provider: "github",
repo: "repo/name",
directory: "/",
branch: "/$({curl,127.0.0.1})",
)
repo_contents_path = "./file/path"
fetcher = Dependabot::FileFetchers.for_package_manager("bundler").
new(source: source, credentials: [],
repo_contents_path: repo_contents_path)
fetcher.clone_repo_contents
The fix was applied to version 0.125.1
: https://github.com/dependabot/dependabot-core/pull/2727
Escape the branch name prior to passing it to the Dependabot::Source
class.
For example using shellwords
:
require "shellwords"
branch = Shellwords.escape("/$({curl,127.0.0.1})")
source = Dependabot::Source.new(
provider: "github",
repo: "repo/name",
directory: "/",
branch: branch,
)
{ "nvd_published_at": "2020-11-13T16:15:18Z", "cwe_ids": [ "CWE-74" ], "severity": "HIGH", "github_reviewed": true, "github_reviewed_at": "2020-11-13T15:47:18Z" }