Advanced Usage

GitHub Security Advisory

To download security advisories from GitHub, a personal access token with minimal permissions is necessary.

• Fine-grained token: Grant no permissions and select the following for repository access: Public Repositories (read-only)
• Token (classic): Grant no permissions

export GITHUB_TOKEN="<PAT token>"

Suggest mode

Depscan comes with a suggest mode enabled by default to simplify the triaging experience. The fix version for each vulnerability is retrieved from the sources. Sometimes, there might be known vulnerabilities in the fix version reported. Eg: in the below screenshot the fix versions suggested for jackson-databind might contain known vulnerabilities.

Notice, how the new suggested version is 2.9.10.5 which is an optimal fix version. Please note that the optimal fix version may not be the appropriate version for your application based on compatibility.

Pass --no-suggest to disable this behavior.

Package Risk audit

--risk-audit argument enables package risk audit. Currently, only npm and PyPI packages are supported in this mode. Some risk factors are identified and assigned weights to compute a final risk score. Packages that then exceed a maximum risk score (config.pkg_max_risk_score) are presented in a table.

Use --private-ns to specify the private package namespace that should be checked for dependency confusion type issues where a private package is available on the public npm/pypi registry.

For example, to check if private packages with namespaces @appthreat and @shiftleft are not accidentally made public, use the below argument.

--private-ns appthreat,shiftleft

Risk category	Default Weight	Reason
pkg_private_on_public_registry	4	Private package is available on a public registry
pkg_min_versions	2	Packages with less than 3 versions represent an extreme where they could be either super stable or quite recent. Special heuristics are applied to ignore older stable packages
mod_create_min_seconds	1	Less than 12 hours difference between modified and creation time. This indicates that the upload had a defect that had to be rectified immediately. Sometimes, such a rapid update could also be malicious
latest_now_min_seconds	0.5	Less than 12 hours difference between the latest version and the current time. Depending on the package such a latest version may or may not be desirable
latest_now_max_seconds	0.5	Package versions that are over 6 years old are in use. Such packages might have vulnerable dependencies that are known or yet to be found
pkg_min_maintainers	2	Package has less than 2 maintainers. Many opensource projects have only 1 or 2 maintainers so special heuristics are used to ignore older stable packages
pkg_min_users	0.25	Package has less than 2 npm users
pkg_install_scripts	2	Package runs a custom pre or post installation scripts. This is often malicious and a downside of npm.
pkg_node_version	0.5	Package supports outdated version of node such as 0.8, 0.10, 4 or 6.x. Such projects might have prototype pollution or closure related vulnerabilities
pkg_scope	4 or 0.5	Packages that are used directly in the application (required scope) gets a score with a weight of 4. Optional packages get a score of 0.25
deprecated	1	Latest version is deprecated

Refer to pkg_query.py::get_category_score method for the risk formula.

Automatic adjustment

A parameter called created_now_quarantine_seconds is used to identify packages that are safely past the quarantine period (1 year). Certain risks such as pkg_min_versions and pkg_min_maintainers are suppressed for packages past the quarantine period. This adjustment helps reduce noise since it is unlikely that a malicious package can exist in a registry unnoticed for over a year.

Configuring weights

All parameters can be customized by using environment variables. For eg:

export PKG_MIN_VERSIONS=4 to increase and set the minimum versions category to 4.

Live OS scan

By passing -t os, depscan can generate an SBOM for a live operating system or a VM with OS packages and kernel information. Optionally, pass the argument --deep to generate an SBOM with both OS and application packages and to check for application vulnerabilities.

All OS packages.

depscan -t os -i . -o reports/depscan.json

All OS and application packages.

depscan -t os --deep -i . -o reports/depscan.json

License scan

dep-scan can scan the dependencies for any license limitations and report them directly on the console log. To enable license scanning set the environment variable FETCH_LICENSE to true.

export FETCH_LICENSE=true

The license data is sourced from choosealicense.com and is quite limited. If the license of a given package cannot be reliably matched against this list it will get silently ignored to reduce any noise. This behavior could change in the future once the detection logic gets improved.

Kubernetes and Cloud apps

dep-scan could auto-detect most cloud applications and Kubernetes manifest files. Pass the argument -t yaml-manifest to manually specify the type.

PDF reports

Ensure wkhtmltopdf is installed or use the official container image to generate pdf reports. Use with --explain for more detailed reports.

Custom reports

dep-scan can be provided with a Jinja template using the --report-template parameter. Giving it will pass the vulnerability report into your template for rendering the report.

Please find a basic example here:

{% if metadata -%}
Report for {{ metadata.component.group }}:{{ metadata.component.name }}:{{ metadata.component.version }}
{% endif -%}

{% if vulnerabilities -%}
There were {{ vulnerabilities | length }} issues identified:

{% for vuln in vulnerabilities -%}
* {{ vuln['bom-ref'] }} - {{ vuln.recommendation }}
{% endfor -%}
{% else -%}
🏆 _No vulnerabilities found_
{% endif -%}

Severity counts:
* Low: {{ summary.LOW }}
* Medium: {{ summary.MEDIUM }}
* High: {{ summary.HIGH }}
* Critical: {{ summary.CRITICAL }}
* Unspecified: {{ summary.UNSPECIFIED }}

The objects available are taken from the CycloneDX *.vdr.json BOM file generated, just have a look at the file for its full structure:

• metadata
• vulnerabilities
• components
• dependencies
• services

summary is a dictionary type with vulnerability severity quantities as shown in the example above. pkg_vulnerabilities - Same as vulnerabilities from the VDR pkg_group_rows - List of vulnerability id and the dependency tree prioritized by depscan.

Furthermore, insights are imaginable to be made available to the template, please reach out or contribute on demand. We appreciate it if you like to contribute your report templates as examples, please add/find them here.