What is the CVSS score of CVE-2021-39219?

CVE-2021-39219 has a CVSS 3.1 base score of 6.3 (Medium). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H. EPSS exploitation probability: 0.4%.

Is there a patch available for CVE-2021-39219?

Yes, a patch is available for CVE-2021-39219. Update the affected software to the latest version immediately.

Wasmtime CVE-2021-39219

MEDIUM

Access of Resource Using Incompatible Type (Type Confusion) (CWE-843)

2021-09-17 security-advisories@github.com

Memory Corruption Information Disclosure Wasmtime Fedora

6.3

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

6.3 MEDIUM

AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Sep 17, 2021 - 20:15 nvd

MEDIUM 6.3

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

15 cargo packages depend on wasmtime (14 direct, 1 indirect)

Ecosystem-wide dependent count for version 0.30.0.

DescriptionNVD

Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the wasmtime crate clearly marks which functions are safe and which are unsafe, guaranteeing that if consumers never use unsafe then it should not be possible to have memory unsafety issues in their embeddings of Wasmtime. An issue was discovered in the safe API of Linker::func_* APIs. These APIs were previously not sound when one Engine was used to create the Linker and then a different Engine was used to create a Store and then the Linker was used to instantiate a module into that Store. Cross-Engine usage of functions is not supported in Wasmtime and this can result in type confusion of function pointers, resulting in being able to safely call a function with the wrong type. Triggering this bug requires using at least two Engine values in an embedding and then additionally using two different values with a Linker (one at the creation time of the Linker and another when instantiating a module with the Linker). It's expected that usage of more-than-one Engine in an embedding is relatively rare since an Engine is intended to be a globally shared resource, so the expectation is that the impact of this issue is relatively small. The fix implemented is to change this behavior to panic!() in Rust instead of silently allowing it. Using different Engine instances with a Linker is a programmer bug that wasmtime catches at runtime. This bug has been patched and users should upgrade to Wasmtime version 0.30.0. If you cannot upgrade Wasmtime and are using more than one Engine in your embedding it's recommended to instead use only one Engine for the entire program if possible. An Engine is designed to be a globally shared resource that is suitable to have only one for the lifetime of an entire process. If using multiple Engines is required then code should be audited to ensure that Linker is only used with one Engine.

AnalysisAI

Wasmtime is an open source runtime for WebAssembly & WASI. Rated medium severity (CVSS 6.3). This Access of Resource Using Incompatible Type (Type Confusion) vulnerability could allow attackers to execute arbitrary code by exploiting type confusion in the application.

Technical ContextAI

This vulnerability is classified as Access of Resource Using Incompatible Type (Type Confusion) (CWE-843), which allows attackers to execute arbitrary code by exploiting type confusion in the application. Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the wasmtime crate clearly marks which functions are safe and which are unsafe, guaranteeing that if consumers never use unsafe then it should not be possible to have memory unsafety issues in their embeddings of Wasmtime. An issue was discovered in the safe API of Linker::func_* APIs. These APIs were previously not sound when one Engine was used to create the Linker and then a different Engine was used to create a Store and then the Linker was used to instantiate a module into that Store. Cross-Engine usage of functions is not supported in Wasmtime and this can result in type confusion of function pointers, resulting in being able to safely call a function with the wrong type. Triggering this bug requires using at least two Engine values in an embedding and then additionally using two different values with a Linker (one at the creation time of the Linker and another when instantiating a module with the Linker). It's expected that usage of more-than-one Engine in an embedding is relatively rare since an Engine is intended to be a globally shared resource, so the expectation is that the impact of this issue is relatively small. The fix implemented is to change this behavior to panic!() in Rust instead of silently allowing it. Using different Engine instances with a Linker is a programmer bug that wasmtime catches at runtime. This bug has been patched and users should upgrade to Wasmtime version 0.30.0. If you cannot upgrade Wasmtime and are using more than one Engine in your embedding it's recommended to instead use only one Engine for the entire program if possible. An Engine is designed to be a globally shared resource that is suitable to have only one for the lifetime of an entire process. If using multiple Engines is required then code should be audited to ensure that Linker is only used with one Engine. Affected products include: Bytecodealliance Wasmtime, Fedoraproject Fedora. Version information: version 0.30.0.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Enforce strict type checking, use type-safe languages, validate object types before operations.