# CVE-2020-1787: Auth bypass in HUAWEI Mate 20

> A logic error allows a guest user to bypass the host user's screen lock and access their desktop, requiring a system update.

- **Severity:** Medium 6.6 (`CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jan 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-pq48-j2pq-xj5j

## What is CVE-2020-1787?

CVE-2020-1787 is a medium-severity authentication bypass vulnerability in HUAWEI Mate 20, published on 9 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

HUAWEI Mate 20 smartphones versions earlier than 9.1.0.139(C00E133R3P1) have an improper authentication vulnerability. The system has a logic error under certain scenario, successful exploit could allow the attacker who gains the privilege of guest user to access to the host user's desktop in an instant, without unlocking the screen lock of the host user.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2020-1787?

It affects 1 product.


Products: Huawei Mate 20 Firmware.

## How do I fix CVE-2020-1787?

No fix has been published for CVE-2020-1787 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1787 being exploited?

There is no known exploitation of CVE-2020-1787 in the wild and no public exploit code.

## Other vulnerabilities in HUAWEI Mate 20

- [CVE-2020-9113](https://insights.sbomify.com/CVE-2020-9113/): Memory corruption in HUAWEI Mate 20 (high 8.0)
- [CVE-2019-5225](https://insights.sbomify.com/CVE-2019-5225/): Memory corruption in P30, Mate 20, P30 Pro (high 7.8)
- [CVE-2020-1796](https://insights.sbomify.com/CVE-2020-1796/): Missing authorization in HUAWEI Mate 20;HUAWEI Mate 30 Pro (medium 6.6)
- [CVE-2020-1840](https://insights.sbomify.com/CVE-2020-1840/): Auth bypass in HUAWEI Mate 20 (medium 6.0)
- [CVE-2018-7956](https://insights.sbomify.com/CVE-2018-7956/): Huawei VIP App is a mobile app for Malaysia customers that purchased P20 Series, Nova 3/3i and Mate 20. (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1787 and fix it if it is affected.

What it is: CVE-2020-1787 is a medium-severity authentication bypass vulnerability in HUAWEI Mate 20, published on 9 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-1787 in the wild and no public exploit code.

Affected product: HUAWEI Mate 20. 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-2020-1787/ (Markdown: https://insights.sbomify.com/CVE-2020-1787/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1787
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1787
- OSV: https://osv.dev/vulnerability/CVE-2020-1787

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-1787/
Summaries are generated and may contain mistakes; the official description above is the record.