[20] [MODERATE] Use of Insufficiently Random Values in undici #460

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opened 2025-06-04 18:37:40 +01:00 by Vylpes · 1 comment

Vylpes commented

2025-06-04 18:37:40 +01:00

Owner

Package: undici
Affected versions: >= 6.0.0, < 6.21.1
Patched version: 6.21.1

Impact

Undici fetch() uses Math.random() to choose the boundary for a multipart/form-data request. It is known that the output of Math.random() can be predicted if several of its generated values are known.

If there is a mechanism in an app that sends multipart requests to an attacker-controlled website, they can use this to leak the necessary values. Therefore, An attacker can tamper with the requests going to the backend APIs if certain conditions are met.

Patches

This is fixed in 5.28.5; 6.21.1; 7.2.3.

Workarounds

Do not issue multipart requests to attacker controlled servers.

Package: `undici` Affected versions: `>= 6.0.0, < 6.21.1` Patched version: `6.21.1` --- ## Impact Undici fetch() uses Math.random() to choose the boundary for a multipart/form-data request. It is known that the output of Math.random() can be predicted if several of its generated values are known. If there is a mechanism in an app that sends multipart requests to an attacker-controlled website, they can use this to leak the necessary values. Therefore, An attacker can tamper with the requests going to the backend APIs if certain conditions are met. ## Patches This is fixed in 5.28.5; 6.21.1; 7.2.3. ## Workarounds Do not issue multipart requests to attacker controlled servers.