CVE-2022-39218 Random number seed fixed during compilation
Predictable random number generation in Fastly's JS Compute Runtime allows attackers to bypass cryptographic controls and disclose sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-39218?
CVE-2022-39218 is a high-severity vulnerability in fastly js-compute-runtime, published on 20 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-335
Which versions are affected by CVE-2022-39218?
2 open source packages ship an affected version, including @fastly/js-compute. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@fastly/js-compute npm | From 0.4.0 | 0.5.3 |
@fastly/js-compute npm | From 0.4.0 | 0.5.3 |
Products include Fastly Js-Compute.
How do I fix CVE-2022-39218?
Upgrade @fastly/js-compute to 0.5.3 or later.
Is CVE-2022-39218 being exploited?
There is no known exploitation of CVE-2022-39218 in the wild and no public exploit code.
Sources
Also known as GHSA-cmr8-5w4c-44v8.