GHSA-hmw2-7cc7-3qxx found in npm/form-data@4.0.5

[devguard-bot-dev]

GHSA-hmw2-7cc7-3qxx found in npm/form-data@4.0.5

Important

Risk: 3.45 (Low)
CVSS: 7.5

Description

Summary

form-data builds multipart/form-data request bodies. Through v4.0.5, the field name passed to FormData#append and the filename option are concatenated directly into the Content-Disposition header with no escaping of CR (\r), LF (\n), or ". An application that uses untrusted input as a field name or filename therefore lets an attacker terminate the header line and either inject additional headers or smuggle whole additional multipart parts into the request the application forwards to a backend.

This is CWE-93 (CRLF injection). It is a divergence from how browsers and the WHATWG HTML spec serialize form-data (they escape these characters), so the fix is to match that behavior. Severity is conditional: it depends on the consuming application passing attacker-controlled data as a field name or filename. Applications that only use fixed/trusted field names are not affected.

Details

In lib/form_data.js, _multiPartHeader builds the part header as:

'Content-Disposition': ['form-data', 'name="' + field + '"'].concat(contentDisposition || [])

and _getContentDisposition builds filename="' + filename + '"'. Neither escapes control characters, so a \r\n in field/filename ends the header line. The same applies to ", which can break out of the quoted parameter.

Proof of concept

const FormData = require('form-data');
const form = new FormData();
form.append('email"\r\nX-Injected: true\r\nfake="', 'user@example.com');
console.log(form.getBuffer().toString());

Before the fix this emits an injected X-Injected: true header line. A field name that also includes --<boundary> sequences can introduce additional parts (e.g. an extra name="is_admin" field), which a downstream parser accepts as legitimate.

Impact

For an application that uses untrusted field names/filenames:

• Field injection / override (integrity). Inject or override fields the backend trusts (e.g. is_admin, role) — the primary demonstrated impact.
• Header injection into the generated multipart part.

Claims of guaranteed privilege escalation, authentication bypass, high confidentiality impact, and availability impact are application-dependent downstream consequences, not properties of form-data itself, and are not demonstrated by the PoC.

Severity

The demonstrated, library-attributable impact is integrity (field/header injection); there is no demonstrated confidentiality disclosure or availability impact in form-data itself, and exploitation requires the consuming app to feed untrusted data into field names/filenames. A Moderate (≈5.3, I:L) rating is also defensible given that precondition.

Patch

Fixed in 4.0.6, 3.0.5, and 2.5.6. Users on older 0.x/1.x/2.x releases should upgrade to 2.5.6 or later.

The fix escapes \r, \n, and " as %0D, %0A, and %22 in field names and filenames, matching the WHATWG HTML multipart/form-data encoding algorithm that browsers implement. This neutralizes the injection while leaving ordinary field names (including name[0], dotted, and unicode names) unchanged.

Workaround

Until upgrading, validate or reject field names/filenames that contain control characters before calling append:

if (/[\r\n]/.test(field)) { throw new Error('invalid field name'); }

Credit

Reported by yueyueL.

Affected component

The vulnerability is in pkg:npm/form-data@4.0.5, found in artifacts pkg:oci/l3montree-cybersecurity/devguard/devguard-documentation.

Recommended fix

Upgrade to version 4.0.6 or later.

# Update all vulnerable npm packages
npm audit fix
# Update only this package
npm install form-data@4.0.6 

Additional guidance for mitigating vulnerabilities

Visit our guides on devguard.org

See more details...

Path to component

 %%{init: { 'theme':'base', 'themeVariables': {
'primaryColor': '#F3F3F3',
'primaryTextColor': '#0D1117',
'primaryBorderColor': '#999999',
'lineColor': '#999999',
'secondaryColor': '#ffffff',
'tertiaryColor': '#ffffff'
} }}%%
 flowchart TD
Your_application(["Your application"]) --- pkg_npm_form_data_4_0_5(["pkg:npm/form-data\@4.0.5"])

classDef default stroke-width:2px

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Risk Factor	Value	Description
Vulnerability Depth	1	The vulnerability is in a direct dependency of your project.
EPSS	0.00 %	The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
EXPLOIT	Not available	We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database. There are no script kiddies exploiting this vulnerability.
CVSS-BE	7.5	- Exploiting this vulnerability significantly impacts integrity.
CVSS-B	7.5	- The vulnerability can be exploited over the network without needing physical access. - It is easy for an attacker to exploit this vulnerability. - An attacker does not need any special privileges or access rights. - No user interaction is needed for the attacker to exploit this vulnerability. - The impact is confined to the system where the vulnerability exists. - There is a high impact on the integrity of the data.

More details can be found in DevGuard

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[devguard-bot-dev]

Risk exceeds predefined threshold