# CVE-2021-25836: Business logic in n/a

> Attackers can exploit cache inconsistency to persist failed transaction bytecode, enabling the creation of malicious honeypot contracts in Cosmos Network Ethermint.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/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:** 8 Feb 2021
- **Updated:** 3 Aug 2024

## What is CVE-2021-25836?

CVE-2021-25836 is a high-severity vulnerability in n/a, published on 8 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Cosmos Network Ethermint <= v0.4.0 is affected by cache lifecycle inconsistency in the EVM module. The bytecode set in a FAILED transaction wrongfully remains in memory(stateObject.code) and is further written to persistent store at the Endblock stage, which may be utilized to build honeypot contracts.

## Which versions are affected by CVE-2021-25836?

It affects 1 product.


Products: Chainsafe Ethermint.

## How do I fix CVE-2021-25836?

No fix has been published for CVE-2021-25836 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-25836 being exploited?

There is no known exploitation of CVE-2021-25836 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-25834](https://insights.sbomify.com/CVE-2021-25834/): Authentication bypass by capture-replay in github.com/cosmos/ethermint (high 7.5)
- [CVE-2021-25835](https://insights.sbomify.com/CVE-2021-25835/): Authentication bypass by capture-replay in github.com/cosmos/ethermint (high 7.5)
- [CVE-2021-25837](https://insights.sbomify.com/CVE-2021-25837/): Business logic in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-25836 and fix it if it is affected.

What it is: CVE-2021-25836 is a high-severity vulnerability in n/a, published on 8 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-25836 in the wild and no public exploit code.

Affected product: n/a. 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-2021-25836/ (Markdown: https://insights.sbomify.com/CVE-2021-25836/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25836
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25836
- OSV: https://osv.dev/vulnerability/CVE-2021-25836

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-25836/
Summaries are generated and may contain mistakes; the official description above is the record.