# CVE-2019-19920: Code injection in n/a

> Attackers can execute arbitrary code in sa-exim by writing malicious configuration files due to unsafe eval usage in Greylisting.pm.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Dec 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-19920, DLA-2062-1, GHSA-28xw-m7jp-89ch, UBUNTU-CVE-2019-19920, USN-4520-1

## What is CVE-2019-19920?

CVE-2019-19920 is a high-severity code injection vulnerability in Canonical Ubuntu Linux, published on 22 Dec 2019. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

sa-exim 4.2.1 allows attackers to execute arbitrary code if they can write a .cf file or a rule. This occurs because Greylisting.pm relies on eval (rather than direct parsing and/or use of the taint feature). This issue is similar to CVE-2018-11805.

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

## Which versions are affected by CVE-2019-19920?

It affects 3 products.


Products: Canonical Ubuntu Linux, Debian Debian Linux, Sa-Exim Project Sa-Exim.

## How do I fix CVE-2019-19920?

Apply the vendor's patch.

## Is CVE-2019-19920 being exploited?

There is no known exploitation of CVE-2019-19920 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-19920 and fix it if it is affected.

What it is: CVE-2019-19920 is a high-severity code injection vulnerability in Canonical Ubuntu Linux, published on 22 Dec 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-19920 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. 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-2019-19920/ (Markdown: https://insights.sbomify.com/CVE-2019-19920/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-19920
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-19920
- OSV: https://osv.dev/vulnerability/CVE-2019-19920

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-19920/
Summaries are generated and may contain mistakes; the official description above is the record.