GitHub Advisoryadvisory · RubyGems

GHSA-23f7-99jx-m54r Remote code execution in dependabot-core branch names when cloning

HIGH Published 2020-11-13 Modified 2023-05-16 Official page ↗
Aliases
CVE-2020-26222
Ecosystem
RubyGems
Packages
dependabot-omnibus, dependabot-common
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Weaknesses
CWE-74
Reviewed
2020-11-13

Affected packages

• RubyGems dependabot-omnibus: >= 0.119.0.beta1, < 0.125.1 → fixed in 0.125.1 • RubyGems dependabot-common: >= 0.119.0.beta1, < 0.125.1 → fixed in 0.125.1

Description

Impact 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: `"/$({curl,127.0.0.1})"`, Dependabot will make a HTTP request to the following URL: 127.0.0.1 when cloning the source repository. When Dependabot is configured to clone the source repository during an update, Dependabot runs a shell command to git clone the repository: ```bash git clone --no-tags --no-recurse-submodules --depth=1 --branch= --single-branch repo/contents/path ``` Dependabot will always clone the source repository for `go_modules` during the file fetching step and can be configured to clone the repository for other package managers using the `FileFetcher` class from `dependabot-common`. ```ruby source = Dependabot::Source.new( provider: "github", repo: "repo/name", directory: "/", branch: "/$({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 ``` Patches The fix was applied to version `0.125.1`: https://github.com/dependabot/dependabot-core/pull/2727 Workarounds Escape the branch name prior to passing it to the `Dependabot::Source` class. For example using `shellwords`: ```ruby require "shellwords" branch = Shellwords.escape("/$({curl,127.0.0.1})") source = Dependabot::Source.new( provider: "github", repo: "repo/name", directory: "/", branch: branch, ) ```

Related

Alias · CVE (1)

  • CVE-2020-26222 Dependabot is a set of packages for automated dependency management for Ruby, JavaScript, Python, PHP, Elixir, Rust, Java, .NET, Elm and Go. vulnerability

Weakness · CWE (1)

  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component weakness

References