CVE-2023-46232 era-compiler-vyper First Immutable Variable Initialization vulnerability
A compiler bug causes incorrect initialization of immutable variables in Vyper contracts, leading to data corruption that requires upgrading and redeploying contracts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2023-46232?
CVE-2023-46232 is a medium-severity vulnerability in matter-labs era-compiler-vyper, published on 25 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
era-compiler-vyper is the EraVM Vyper compiler for zkSync Era, a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum. Prior to era-compiler-vype version 1.3.10, a bug prevented the initialization of the first immutable variable for Vyper contracts meeting certain criteria. The problem arises when there is a String or Array with more 256-bit words allocated than initialized. It results in the second word’s index unset, that is effectively set to 0, so the first immutable value with the actual 0 index is overwritten in the ImmutableSimulator. Version 1.3.10 fixes this issue by setting all indexes in advance. The problem will go away, but it will get more expensive if the user allocates a lot of uninitialized space, e.g. `String[4096]`. Upgrading and redeploying affected contracts is the only way of working around the issue.
Weakness: CWE-471
Which versions are affected by CVE-2023-46232?
It affects 1 product.
Products include Matter-Labs Zkvyper.
How do I fix CVE-2023-46232?
No fix has been published for CVE-2023-46232 yet. Limit exposure of the affected software until one is available.
Is CVE-2023-46232 being exploited?
There is no known exploitation of CVE-2023-46232 in the wild and no public exploit code.
Other vulnerabilities in matter-labs era-compiler-vyper
Sources
Also known as GHSA-h8jv-969m-94r4.