# CVE-2019-12420: Denial of service in Apache SpamAssassin

> Attackers can craft messages to exhaust resources in Apache SpamAssassin, causing denial of service; administrators should upgrade immediately.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Dec 2019
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2019-12420, DEBIAN-CVE-2019-12420, GHSA-q6ww-c56f-5fhw, RHSA-2020:3973, UBUNTU-CVE-2019-12420

## What is CVE-2019-12420?

CVE-2019-12420 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 12 Dec 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Apache SpamAssassin before 3.4.3, a message can be crafted in a way to use excessive resources. Upgrading to SA 3.4.3 as soon as possible is the recommended fix but details will not be shared publicly.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2019-12420?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `spamassassin` | Red Hat:enterprise_linux:7::client | All versions | 0:3.4.0-6.el7 |
| `spamassassin-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.4.0-6.el7 |
| `spamassassin` | Red Hat:enterprise_linux:7::server | All versions | 0:3.4.0-6.el7 |
| `spamassassin-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:3.4.0-6.el7 |
| `spamassassin` | Red Hat:enterprise_linux:7::workstation | All versions | 0:3.4.0-6.el7 |
| `spamassassin-debuginfo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:3.4.0-6.el7 |

Products: Apache Spamassassin, Debian Debian Linux.

## How do I fix CVE-2019-12420?

Upgrade to a fixed version.

## Is CVE-2019-12420 being exploited?

There is no known exploitation of CVE-2019-12420 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2020-1946](https://insights.sbomify.com/CVE-2020-1946/): Apache SpamAssassin has an OS Command Injection vulnerability (critical 9.8)
- [CVE-2018-11780](https://insights.sbomify.com/CVE-2018-11780/): Code injection in Apache SpamAssassin (critical 9.8)
- [CVE-2020-1930](https://insights.sbomify.com/CVE-2020-1930/): Command injection in Apache SpamAssassin (high 8.1)
- [CVE-2020-1931](https://insights.sbomify.com/CVE-2020-1931/): Command injection in Apache SpamAssassin (high 8.1)
- [CVE-2018-11781](https://insights.sbomify.com/CVE-2018-11781/): Apache SpamAssassin 3.4.2 fixes a local user code injection in the meta rule syntax. (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-12420 and fix it if it is affected.

What it is: CVE-2019-12420 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 12 Dec 2019. 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-2019-12420 in the wild and no public exploit code.

Affected product: Debian Debian 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-2019-12420/ (Markdown: https://insights.sbomify.com/CVE-2019-12420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-12420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-12420
- OSV: https://osv.dev/vulnerability/CVE-2019-12420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-12420/
Summaries are generated and may contain mistakes; the official description above is the record.