Sharon KatzandLucas Manuel Rodriguez
24e64614aa
Resolves https://github.com/fleetdm/confidential/issues/16902 - [x] Changes file added for user-visible changes in `changes/`, `orbit/changes/` or `ee/fleetd-chrome/changes`. ## Testing - [x] Added/updated automated tests - [x] QA'd all new/changed functionality manually ## Reproduction **Attack vector:** An authenticated Fleet admin uploads a crafted `.msi` file via the software upload API. The server's MSI metadata parser (`pkg/file/msi.go` > `ExtractMSIMetadata` > `decodeStrings`) processes the file's `_StringPool` and `_StringData` streams during upload. A malicious `_StringPool` can claim arbitrarily large string sizes that trigger speculative memory allocation before the actual data is read. **Manual reproduction:** Wrote a standalone Go program that constructs the two raw byte streams the parser consumes (a 12-byte `_StringPool` claiming a 64 MB string, and an empty 0-byte `_StringData`), then measures heap allocation via `runtime.MemStats` before and after calling the vulnerable code path. **Before fix (vulnerable):** ``` Pool input size: 12 bytes StringData size: 0 bytes Claimed string size: 67108864 bytes (64 MB) Error returned: failed to read string data: EOF Heap allocated: 67117016 bytes (64.0 MB) Amplification: 12 input bytes -> 67117016 byte allocation (5593084x) ``` 12 bytes of pool input forced a 64 MB heap allocation via `buf.Grow()` before `io.CopyN` discovered there was no data to read. **After fix:** ``` Error returned: failed to read string data: EOF Heap allocated: 3072 bytes (3.0 KB) Memory amplification eliminated: true ``` Same input, 3 KB allocated instead of 64 MB. Without the speculative `buf.Grow()`, `io.CopyN` grows the buffer incrementally based on actual available data and immediately hits EOF. <!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit - **Bug Fixes** - Fixed a potential resource exhaustion issue when processing MSI metadata with unusually large string-size declarations. - MSI files with missing string data are now handled without excessive memory allocation. <!-- end of auto-generated comment: release notes by coderabbit.ai --> --------- Co-authored-by: Lucas Manuel Rodriguez <lucas@fleetdm.com>
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Open-source platform for IT and security teams with thousands of computers. Designed for APIs, GitOps, webhooks, YAML, and humans.
What's it for?
Fleet gives you a single system to secure and maintain all your computing devices over the air. You can do MDM, patch stuff, deploy software, and verify anything, all from one place, across every OS your organization uses.
Fleet works directly with data and events from the native operating system, down to the bare metal. Strong diagnostics let you investigate errors on end-user devices and collect accurate audit evidence in minutes.
Get started
You can try Fleet out for yourself, or grab time with one of the maintainers to chat.
Is it any good?
Fleet is used in production by IT and security teams managing thousands of devices. Many deployments support tens of thousands of hosts, and a few large organizations manage 400,000 or more.
Supported platforms
- Linux (all distros)
- macOS
- Windows
- Chromebooks
- iOS and Android (BYOD or corporate-owned)
- Amazon Web Services (AWS)
- Google Cloud (GCP)
- Azure (Microsoft cloud)
- Data centers
- Containers (kube, etc)
- Linux-based IoT devices
Infrastructure as code
Manage your fleet with GitOps, or use the GUI, REST API, webhook events, and the fleetctl command-line tool.
Linux support
First-class support for all major distros. Linux gets the same attention and visibility as macOS and Windows.
Visibility and compliance
Fleet can report on hundreds of attributes across your devices and ships with CIS benchmarks for macOS and Windows and comprehensive operating system, hardware, and software data. Check out the table reference documentation to see what's available.
Open by design
Fleet is open source and transparent about what it can and can't see. End users can verify exactly how the agent works and what data their company collects. Fleet collects only the data needed to manage and secure devices, not private activity like keystrokes, emails, or webcams.
Good neighbors
Ready-to-use, enterprise-friendly integrations exist for Snowflake, Splunk, GitHub Actions, Vanta, Elastic Jira, Zendesk, and more. Fleet also works with tools such as Munki, Chef, Puppet, Ansible, CrowdStrike, and SentinelOne.
Lighter than air
Fleet is lightweight and modular. You can use it for MDM without using it for security, and vice versa. You can turn off features you are not using.
Free as in free
The free version of Fleet will always be free. Fleet is independently backed and actively maintained with the help of many amazing contributors.
Longevity
The company behind Fleet is founded (and majority-owned) by true believers in open source. The company's business model is influenced by GitLab (NYSE: GTLB), with great investors, happy customers, and the capacity to become profitable at any time.
Fleet Device Management's company handbook is public and open source. You can read about the history of Fleet and our commitment to improving the product.
Chat
The Fleet community is full of kind and helpful people. Whether or not you are a paying customer, if you need help, just reach out.
Contributing 
Contributions are welcome, whether you answer questions on Slack / GitHub / LinkedIn, improve the documentation or website, write a tutorial, give a talk at a conference or local meetup, give an interview on a podcast, troubleshoot reported issues, or submit a patch. The Fleet code of conduct is on GitHub.
License
The free version of Fleet is available under the MIT license. The commercial license is also designed to allow contributions to paid features for users whose employment agreements allow them to contribute to open source projects. (See LICENSE.md for details.)
Fleet is built on osquery, nanoMDM, Nudge, and swiftDialog.