# CVE-2019-18894: Command injection in n/a

> Attackers can execute arbitrary OS commands via a crafted request to the local web server, allowing sandbox escape from browser extensions.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Jan 2020
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-8g22-628c-4vg2

## What is CVE-2019-18894?

CVE-2019-18894 is a high-severity command injection vulnerability in n/a, published on 13 Jan 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

In Avast Premium Security 19.8.2393, attackers can send a specially crafted request to the local web server run by Avast Antivirus on port 27275 to support Bank Mode functionality. A flaw in the processing of a command allows execution of arbitrary OS commands with the privileges of the currently logged in user. This allows for example attackers who compromised a browser extension to escape from the browser sandbox.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2019-18894?

It affects 1 product.


Products: Avast Premium Security.

## How do I fix CVE-2019-18894?

No fix has been published for CVE-2019-18894 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-18894 being exploited?

There is no known exploitation of CVE-2019-18894 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-42125](https://insights.sbomify.com/CVE-2023-42125/): Avast Premium Security Sandbox Protection Link Following Privilege Escalation Vulnerability (high 7.8)
- [CVE-2022-28964](https://insights.sbomify.com/CVE-2022-28964/): Path traversal in n/a (high 7.1)
- [CVE-2022-28965](https://insights.sbomify.com/CVE-2022-28965/): Other in n/a (medium 6.5)
- [CVE-2021-27241](https://insights.sbomify.com/CVE-2021-27241/): Path traversal in Premium Security (medium 6.1)
- [CVE-2023-42124](https://insights.sbomify.com/CVE-2023-42124/): Avast Premium Security Sandbox Protection Incorrect Authorization Privilege Escalation Vulnerability (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-18894 and fix it if it is affected.

What it is: CVE-2019-18894 is a high-severity command injection vulnerability in n/a, published on 13 Jan 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-18894 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-2019-18894/ (Markdown: https://insights.sbomify.com/CVE-2019-18894/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18894
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18894
- OSV: https://osv.dev/vulnerability/CVE-2019-18894

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-18894/
Summaries are generated and may contain mistakes; the official description above is the record.