CVE-2022-39218

Random number seed fixed during compilation

State
Published
Severity
7.5 High
Published
Sep 20, 2022
Updated
Apr 23, 2025
Reserved
Sep 2, 2022

Read the record on cve.org

Description

The JS Compute Runtime for Fastly's Compute@Edge platform provides the environment JavaScript is executed in when using the Compute@Edge JavaScript SDK. In versions prior to 0.5.3, the `Math.random` and `crypto.getRandomValues` methods fail to use sufficiently random values. The initial value to seed the PRNG (pseudorandom number generator) is baked-in to the final WebAssembly module, making the sequence of random values for that specific WebAssembly module predictable. An attacker can use the fixed seed to predict random numbers generated by these functions and bypass cryptographic security controls, for example to disclose sensitive data encrypted by functions that use these generators. The problem has been patched in version 0.5.3. No known workarounds exist.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NGitHub_M

Weaknesses

  • CWE-335 Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)

Affected Products

ProductVersions
js-compute-runtimefastly
  • < 0.5.3Affected

References

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