# CVE-2024-34704: era-compiler-solidity contains a `xor(zext(cmp), -1)` misoptimization

> A misoptimization in the ZKsync Solidity compiler incorrectly transforms boolean logic, potentially leading to incorrect smart contract behavior.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 May 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-22pj-7cvw-r3gc

## What is CVE-2024-34704?

CVE-2024-34704 is a medium-severity vulnerability in matter-labs era-compiler-solidity, published on 13 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

era-compiler-solidity is the ZKsync compiler for Solidity.  The problem occurred during instruction selection in the `DAGCombine` phase while visiting the XOR operation. The issue arises when attempting to fold the expression `!(x cc y)` into `(x !cc y)`. To perform this transformation, the second operand of XOR should be a constant representing the true value. However, it was incorrectly assumed that -1 represents the true value, when in fact, 1 is the correct representation, so this transformation for this case should be skipped. This vulnerability is fixed in 1.4.1.

Weakness: CWE-682 (Incorrect Calculation)

## Which versions are affected by CVE-2024-34704?


## How do I fix CVE-2024-34704?

No fix has been published for CVE-2024-34704 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-34704 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-34704 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-34704 and fix it if it is affected.

What it is: CVE-2024-34704 is a medium-severity vulnerability in matter-labs era-compiler-solidity, published on 13 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-34704 exists.

Affected product: matter-labs era-compiler-solidity. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-34704/ (Markdown: https://insights.sbomify.com/CVE-2024-34704/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-34704
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-34704
- OSV: https://osv.dev/vulnerability/CVE-2024-34704

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From sbomify Insights: https://insights.sbomify.com/CVE-2024-34704/
Summaries are generated and may contain mistakes; the official description above is the record.