# CVE-2021-0341: Square OkHttp can accept the wrong certificate

> Improper certificate hostname verification in Android allows remote attackers to disclose information without user interaction.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Feb 2021
- **Updated:** 3 Aug 2024
- **Also known as:** A-171980069, ASB-A-171980069, CLEANSTART-2026-BP11951, CLEANSTART-2026-JK31874, CLEANSTART-2026-PY40890, CLEANSTART-2026-ZD25264, CLSA-2025-1766707708, ECHO-de60-1a64-95c9, GHSA-3cqm-mf7h-prrj, MINI-jvp7-xc28-5363, ROOT-APP-MAVEN-CVE-2021-0341

## What is CVE-2021-0341?

CVE-2021-0341 is a high-severity vulnerability in Google Android, published on 10 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In verifyHostName of OkHostnameVerifier.java, there is a possible way to accept a certificate for the wrong domain due to improperly used crypto. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.1 Android-9 Android-10 Android-11Android ID: A-171980069

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2021-0341?

2 open source packages ship an affected version, including com.squareup.okhttp3:okhttp. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.squareup.okhttp3:okhttp` | Maven | All versions | 4.9.2 |
| `com.squareup.okhttp3:okhttp` | Maven | All versions | 4.9.2 |

Products: Google Android.

## How do I fix CVE-2021-0341?

Upgrade com.squareup.okhttp3:okhttp to 4.9.2 or later.

## Is CVE-2021-0341 being exploited?

There is no known exploitation of CVE-2021-0341 in the wild and no public exploit code.

## Other vulnerabilities in Google Android

- [CVE-2026-58704](https://insights.sbomify.com/CVE-2026-58704/): Google Pixel Improper Authorization (high 8.8, exploited in the wild)
- [CVE-2025-48543](https://insights.sbomify.com/CVE-2025-48543/): Android Runtime Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2023-35674](https://insights.sbomify.com/CVE-2023-35674/): Android Framework Privilege Escalation (high 8.8, exploited in the wild)
- [CVE-2025-48595](https://insights.sbomify.com/CVE-2025-48595/): Android Framework Integer Overflow (high 8.4, exploited in the wild)
- [CVE-2024-32896](https://insights.sbomify.com/CVE-2024-32896/): Android Pixel Privilege Escalation (high 8.1, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-0341 and fix it if it is affected.

What it is: CVE-2021-0341 is a high-severity vulnerability in Google Android, published on 10 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-2021-0341 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.squareup.okhttp3:okhttp (Maven): affected all versions; fixed in 4.9.2
- com.squareup.okhttp3:okhttp (Maven): affected all versions; fixed in 4.9.2

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-2021-0341/ (Markdown: https://insights.sbomify.com/CVE-2021-0341/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0341
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0341
- OSV: https://osv.dev/vulnerability/CVE-2021-0341

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-0341/
Summaries are generated and may contain mistakes; the official description above is the record.