JS Compute Runtime for Fastly up to 0.5.2 WebAssembly prng seed

Summaryinfo

A vulnerability labeled as problematic has been found in JS Compute Runtime for Fastly up to 0.5.2. Affected by this vulnerability is an unknown functionality of the component WebAssembly Module. Such manipulation leads to prng seed. This vulnerability is listed as CVE-2022-39218. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in JS Compute Runtime for Fastly up to 0.5.2. Affected by this issue is an unknown part of the component WebAssembly Module. The manipulation with an unknown input leads to a prng seed vulnerability. Using CWE to declare the problem leads to CWE-335. The product uses a Pseudo-Random Number Generator (PRNG) but does not correctly manage seeds. Impacted is confidentiality. CVE summarizes:

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.

The weakness was presented 09/21/2022 as GHSA-cmr8-5w4c-44v8. The advisory is available at github.com. This vulnerability is handled as CVE-2022-39218 since 09/02/2022. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1600.001 by the MITRE ATT&CK project.

Upgrading to version 0.5.3 eliminates this vulnerability.

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Productinfo

Name

• JS Compute Runtime for Fastly

Version

• 0.5.0
• 0.5.1
• 0.5.2

CPE 2.3info

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CPE 2.2info

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