Vulnerability · Published Aug 29, 2024 · Assigned by GitHub_M
CVE-2024-45056`fold (xor (shl 1, x), -1) -> (rotl ~1, x)` misoptimization in zksolc
Medium 5.9
In plain English
A medium-severity security flaw in era-compiler-solidity from matter-labs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).
Official description
zksolc is a Solidity compiler for ZKsync. All LLVM versions since 2015 fold `(xor (shl 1, x), -1)` to `(rotl ~1, x)` if run with optimizations enabled. Here `~1` is generated as an unsigned 64 bits number (`2^64-1`). This number is zero-extended to 256 bits on EraVM target while it should have been sign-extended. Thus instead of producing `roti 2^256 - 1, x` the compiler produces `rotl 2^64 - 1, x`. Analysis has shown that no contracts were affected by the date of publishing this advisory. This issue has been addressed in version 1.5.3. Users are advised to upgrade and redeploy all contracts. There are no known workarounds for this vulnerability.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| matter-labs | era-compiler-solidity | < 1.5.3 |
Weakness: CWE-682 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N