Policy engine
Rules by package name, version range, age, source, license and custom criteria. Block or log-only, with time-limited exceptions. Re-evaluated on every request.
Composer Dependency Firewall: Beta
Composer Dependency Firewall
Packagist accepts packages from anyone, and Composer runs plugin code during install. Bytesafe filters the versions the resolver sees, blocks downloads that fail your firewall rules, and logs every decision.
Bytesafe Dependency Firewall sits in front of your existing repository, protecting developers, CI/CD pipelines and AI agents.
EU-based company · Software supply chain security since 2018.
bytesafe.dev / Firewall
47
Blocked today
1,284
Requests today
12
Active rules
Package
Rule
Status
malicious-pkg@2.1.0
Malware scan
BLOCKED
lodash@4.17.20
CVSS ≥ 7.0
BLOCKED
react@19.1.1
Allowlist
APPROVED
new-release@0.0.1
Age < 7 days
DELAYED
axios@1.7.9
Allowlist
APPROVED
Blocked
malicious-pkg@2.1.0
By Exception
lodash@4.17.21
Delayed
new-release@0.0.1
Approved
react@19.1.1
Early access is open
Run the next generation of our existing Dependency Firewall before general availability.
Supply chain attacks on Composer
A selection of documented supply chain attacks on Composer. The Composer ecosystem has been targeted by malicious packages, account takeovers, and dependency confusion attacks.
php-src backdoor commits2021
Two malicious commits were pushed to the php-src Git server, adding a backdoor disguised as a typo fix. Code review caught it before any release shipped, and the PHP project moved its canonical repository to GitHub. A backdoored release that had reached Packagist would have been subject to malware scanning and a delay window.
Source repo compromiseCVE-2021-294722021
A command injection flaw in how Composer handled package source URLs allowed running commands on Packagist.org itself. The maintainers patched it within a day. An attacker holding that access could have altered metadata or downloads for packages installed millions of times a day.
Registry infrastructurePackagist account takeover2023
A researcher gained access to a maintainer account on Packagist and repointed the repository URLs of 14 widely used packages to forks under their control, showing how a single compromised account can redirect hundreds of millions of installs.
Account takeoverDependency confusionOngoing
Composer resolves names against your configured repositories plus Packagist. If an internal package name is also claimable on Packagist, a public package can resolve ahead of the private one unless repository priority is locked down.
Namespace attackDependency Firewall does not prevent all attacks, but blocks packages that match known malware signatures or violate your policies.
Intercepts every Composer package request before it reaches you.
Every package install is a potential entry point. Traditional SCA tools find problems after packages are already in your environment. Dependency Firewall intercepts every Composer request before it reaches your developers, CI/CD pipelines or AI agents.
You define the rules: block packages with known CVEs, block known malicious packages, or delay newly published versions for a configurable period to give the ecosystem community time to surface zero-day threats.
Works in front of enterprise repository platforms and any Composer registry. No agent installs. No workflow changes.
Public Composer registry
Vulnerable and malicious versions included
Risky packages
Dependency Firewall
Policy engineVetted packages only
Developers and CI/CD
Internal environment
Dependency Firewall capabilities
Policy controls, malware blocking, package delay, dependency confusion protection, publish scanning, and full audit visibility across every Composer request.
Vulnerability blocking
Block packages with known CVEs before install. Filter by CVSS and EPSS severity per registry or team. New advisories take effect immediately.
Malware scanning
Detect malicious payloads, suspicious install hooks and obfuscated code before execution. Quarantined packages are logged and never silently dropped.
Trust downgrade detection
Flags npm releases published with weaker provenance than the version before them, the pattern behind account-takeover attacks. npm only today.
Dependency confusion
Block namespace attacks where public packages impersonate your internal ones. Configurable upstream priority rules ensure private packages always win.
Zero-day safety delay
Hold newly published versions for a configurable window (7 or 14 days) before they reach developers or pipelines. Gives the ecosystem time to surface threats.
Package observations
Every package is fingerprinted: first-seen date, download frequency, requester, version age. Know exactly what passed through and when.
Audit logging
Every block, allow and exception is recorded and exportable to your SIEM. Built to make security teams and auditors happy out of the box.
Publish scanning
Packages are scanned for malware, secrets, and sensitive data before they are published to an upstream registry.
Add a security layer to Composer
Route Composer package traffic through Dependency Firewall, define policies for what's allowed and let the firewall block the rest. Developers and pipelines keep their existing package manager commands.
01
Route Composer requests through Dependency Firewall
Point your Composer configuration at Dependency Firewall. Every install request passes through the firewall before reaching the registry or your environment.
02
Define your security policies
Set vulnerability thresholds, enable malware scanning, configure safety delays for new versions and write allowlist or blocklist rules. Create multiple firewalls with individual rules for different teams or projects.
03
Bad packages are blocked. Safe ones flow through.
Every request is evaluated in real time. Blocked packages are logged with the policy that triggered them. Approved packages are served transparently.
Point Composer at Bytesafe Dependency Firewall
Add the firewall as a Composer repository, then disable the default Packagist repository so nothing resolves around it. The access token goes in the password field of auth.json, kept out of composer.json and out of version control, or in COMPOSER_AUTH for CI. Set a GitHub token on the Packagist upstream so GitHub-hosted downloads keep working once the anonymous rate limit is reached.
Works with the repositories you already use
JFrog Artifactory
Sonatype Nexus
GitLab
GitHub Packages
Azure Artifacts
AWS CodeArtifact
Firewall rules
Each rule targets an ecosystem and applies a condition: vulnerability severity, package age, license type or name pattern. Rules either block or log. Stack multiple rules per firewall. Changes take effect immediately.
Security teams can start with broad guardrails, then narrow policies by upstream, package, version range, internal status, maximum age, CVSS score and EPSS score.
Live firewall logs
Every blocked package is logged: package name, version, status, ecosystem, which firewall evaluated it, which rule triggered and who requested it. Filter by firewall or user.
The log view gives developers a fast answer when an install fails and gives AppSec a complete audit trail for policy enforcement.
Package details and scorecards
Open a package to review advisories, licenses, project metadata, OpenSSF Scorecard checks, dependency counts and source links before deciding whether to block, allow or investigate further.
The package page brings runtime firewall context together with upstream project health. Security teams can compare CVEs, maintainer signals, and repository hygiene from the same screen.
Sits in front of what you already run
Other enterprise dependency firewalls are often bundled into repository platforms. Dependency Firewall is an independent firewall that works with any registry and is built in the EU.
| Criterion | Dependency Firewall | Other enterprise firewalls |
|---|---|---|
| Works with your existing repository | Yes, as a proxy in front of it | Bundled into their platform most often |
| Deploys in minutes | Yes | Usually weeks of platform work most often |
| Predictable pricing | Flat, no usage-based fees | Usage-based or opaque most often |
| EU data sovereignty | Yes | No, US-based most often |
Composer Dependency Firewall: frequently asked questions
Common questions from security and engineering teams.
How do I point Composer at Bytesafe Dependency Firewall?
Add the firewall as a Composer repository with composer config repositories.firewall composer <url>, then run composer config repo.packagist false so nothing resolves around it. Authentication is an access token in the password field of auth.json, or COMPOSER_AUTH in CI. Commit composer.json so every clone and pipeline inherits the config.
Does composer audit still work through the firewall?
Yes. The firewall answers composer audit from its own advisory dataset, so it reports the same advisories as your vulnerability rules and keeps working even when the upstream is a private mirror with no advisory endpoint.
Why does a Composer firewall need a GitHub token?
Packagist is an index, not a package store. Most downloads resolve to api.github.com, which rate-limits unauthenticated requests. Add a GitHub token, no scopes needed, to the Packagist upstream so downloads keep working under load.
Is Composer support production ready?
Composer support is in beta. Composer 2 is required, since Composer 1 reached end of life in 2025. The rule set is already in place: vulnerabilities, abandoned packages, licenses, malware, install-time code execution and release delay. See https://docs.bytesafe.dev/firewall/ecosystems/composer for current detail.
Can different projects have different policies?
Yes. You can create separate firewalls per project. They are lightweight and easy to clone. You can also differentiate by the user or token used for the session. Firewall configurations are small JSON files that can be managed in Git.
Can packages be delayed before they reach developers?
Yes. Dependency Firewall can hold newly published package versions for a configurable window (7 or 14 days) before they reach developers or pipelines. Centralizing delay rules means the protection applies automatically across all teams and pipelines without each project configuring it separately.
What happens if a package passes through but malware is found later?
The firewall tracks all packages via observations: first-seen date, last-seen date, and which firewalls they passed through. When new malware data surfaces, you can see exactly which projects downloaded the affected package and when.
Can firewall rules be automated?
Yes. All configuration is available via API. Configurations can be version-controlled in Git and deployed through your existing automation. All changes are tracked with full rollback support.
Does Dependency Firewall work with enterprise repository platforms?
Yes. Dependency Firewall speaks the same protocols as your package managers, so it is fully transparent to enterprise repository platforms and package registries, including JFrog Artifactory, Sonatype Nexus, GitLab, GitHub Packages and Azure Artifacts.
How is licensing structured?
Two plans: Cloud for SaaS and Enterprise for custom deployment, Managed Cloud or On-Premise. Both include unlimited users, package requests and bandwidth with no usage-based fees. See pricing for plan details and add-ons.
Watch it block Composer threats
Book a 30-minute session and we'll show you how Dependency Firewall fits into your existing setup. Your registries stay unchanged.