CVE-2021-43790 Use After Free in lucet
A use-after-free bug in the Lucet WebAssembly runtime allows attackers to trigger memory corruption or crashes when an Instance object is dropped.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-43790?
CVE-2021-43790 is a high-severity use after free vulnerability in bytecodealliance lucet, published on 29 Nov 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Lucet is a native WebAssembly compiler and runtime. There is a bug in the main branch of `lucet-runtime` affecting all versions published to crates.io that allows a use-after-free in an Instance object that could result in memory corruption, data race, or other related issues. This bug was introduced early in the development of Lucet and is present in all releases. As a result of this bug, and dependent on the memory backing for the Instance objects, it is possible to trigger a use-after-free when the Instance is dropped. Users should upgrade to the main branch of the Lucet repository. Lucet no longer provides versioned releases on crates.io. There is no way to remediate this vulnerability without upgrading.
Weakness: CWE-416
Which versions are affected by CVE-2021-43790?
3 open source packages ship an affected version, including lucet-runtime. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
lucet-runtime crates.io | All versions to 0.6.1 | None |
lucet-runtime crates.io | All versions to 0.6.1 | None |
lucet-runtime crates.io | From 0.0.0-0 | None |
Products include Bytecodealliance Lucet.
How do I fix CVE-2021-43790?
No fix has been published for CVE-2021-43790 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2021-43790 being exploited?
There is no known exploitation of CVE-2021-43790 in the wild and no public exploit code.
Sources
Also known as GHSA-hf79-8hjp-rrvq, RUSTSEC-2021-0155.