[deps] Vault: Update form-data to v4.0.4 [SECURITY]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
form-data	4.0.2 -> 4.0.4

GitHub Vulnerability Alerts

CVE-2025-7783

Summary

form-data uses Math.random() to select a boundary value for multipart form-encoded data. This can lead to a security issue if an attacker:

1. can observe other values produced by Math.random in the target application, and
2. can control one field of a request made using form-data

Because the values of Math.random() are pseudo-random and predictable (see: https://blog.securityevaluators.com/hacking-the-javascript-lottery-80cc437e3b7f), an attacker who can observe a few sequential values can determine the state of the PRNG and predict future values, includes those used to generate form-data's boundary value. The allows the attacker to craft a value that contains a boundary value, allowing them to inject additional parameters into the request.

This is largely the same vulnerability as was recently found in undici by parrot409 -- I'm not affiliated with that researcher but want to give credit where credit is due! My PoC is largely based on their work.

Details

The culprit is this line here: https://github.com/form-data/form-data/blob/426ba9ac440f95d1998dac9a5cd8d738043b048f/lib/form_data.js#L347

An attacker who is able to predict the output of Math.random() can predict this boundary value, and craft a payload that contains the boundary value, followed by another, fully attacker-controlled field. This is roughly equivalent to any sort of improper escaping vulnerability, with the caveat that the attacker must find a way to observe other Math.random() values generated by the application to solve for the state of the PRNG. However, Math.random() is used in all sorts of places that might be visible to an attacker (including by form-data itself, if the attacker can arrange for the vulnerable application to make a request to an attacker-controlled server using form-data, such as a user-controlled webhook -- the attacker could observe the boundary values from those requests to observe the Math.random() outputs). A common example would be a x-request-id header added by the server. These sorts of headers are often used for distributed tracing, to correlate errors across the frontend and backend. Math.random() is a fine place to get these sorts of IDs (in fact, opentelemetry uses Math.random for this purpose)

PoC

PoC here: https://github.com/benweissmann/CVE-2025-7783-poc

Instructions are in that repo. It's based on the PoC from https://hackerone.com/reports/2913312 but simplified somewhat; the vulnerable application has a more direct side-channel from which to observe Math.random() values (a separate endpoint that happens to include a randomly-generated request ID).

Impact

For an application to be vulnerable, it must:

• Use form-data to send data including user-controlled data to some other system. The attacker must be able to do something malicious by adding extra parameters (that were not intended to be user-controlled) to this request. Depending on the target system's handling of repeated parameters, the attacker might be able to overwrite values in addition to appending values (some multipart form handlers deal with repeats by overwriting values instead of representing them as an array)
• Reveal values of Math.random(). It's easiest if the attacker can observe multiple sequential values, but more complex math could recover the PRNG state to some degree of confidence with non-sequential values.

If an application is vulnerable, this allows an attacker to make arbitrary requests to internal systems.

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Release Notes

form-data/form-data (form-data)

v4.0.4

Compare Source

Commits

• [meta] add auto-changelog 811f682
• [Tests] handle predict-v8-randomness failures in node < 17 and node > 23 1d11a76
• [Fix] Switch to using crypto random for boundary values 3d17230
• [Tests] fix linting errors 5e34080
• [meta] actually ensure the readme backup isn’t published 316c82b
• [Dev Deps] update @ljharb/eslint-config 58c25d7
• [meta] fix readme capitalization 2300ca1

v4.0.3

Compare Source

Fixed

• [Fix] append: avoid a crash on nullish values #577

Commits

• [eslint] use a shared config 426ba9a
• [eslint] fix some spacing issues 2094191
• [Refactor] use hasown 81ab41b
• [Fix] validate boundary type in setBoundary() method 8d8e469
• [Tests] add tests to check the behavior of getBoundary with non-strings 837b8a1
• [Dev Deps] remove unused deps 870e4e6
• [meta] remove local commit hooks e6e83cc
• [Dev Deps] update eslint 4066fd6
• [meta] fix scripts to use prepublishOnly c4bbb13

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Configuration

📅 Schedule: Branch creation - "" (UTC), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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This PR was generated by Mend Renovate. View the repository job log.

[github-actions]

Checkmarx One – Scan Summary & Details – 985b622e-5f6a-45a8-8fcf-bf837fd7353f

Great job, no security vulnerabilities found in this Pull Request

[bitwarden-bot]

Internal tracking:

• ID: PM-24010
• Link: https://bitwarden.atlassian.net/browse/PM-24010

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 37.57%. Comparing base (c379651) to head (5359561).
Report is 1 commits behind head on main.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #15712      +/-   ##
==========================================
- Coverage   37.58%   37.57%   -0.01%     
==========================================
  Files        3320     3320              
  Lines       94806    94806              
  Branches    14343    14343              
==========================================
- Hits        35629    35622       -7     
- Misses      57681    57688       +7     
  Partials     1496     1496              

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud