# CVE-2018-18898: Denial of service in n/a

> Remote attackers can cause denial of service in Request Tracker via an algorithmic complexity attack on email address parsing.

- **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:** 17 Mar 2019
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2018-18898, DEBIAN-CVE-2018-18898, DLA-2101-1, GHSA-6rmj-6826-5j8h, UBUNTU-CVE-2018-18898, USN-4517-1

## What is CVE-2018-18898?

CVE-2018-18898 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 17 Mar 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The email-ingestion feature in Best Practical Request Tracker 4.1.13 through 4.4 allows denial of service by remote attackers via an algorithmic complexity attack on email address parsing.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2018-18898?

It affects 4 products.


Products: Bestpractical Request Tracker, Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora.

## How do I fix CVE-2018-18898?

Apply the vendor's patch.

## Is CVE-2018-18898 being exploited?

There is no known exploitation of CVE-2018-18898 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2026-44231](https://insights.sbomify.com/CVE-2026-44231/): RT: Privilege escalation and information disclosure via REST 2.0 user collection endpoint (critical 9.1)
- [CVE-2017-5943](https://insights.sbomify.com/CVE-2017-5943/): Information disclosure in n/a (high 8.8)
- [CVE-2017-5944](https://insights.sbomify.com/CVE-2017-5944/): Code injection in n/a (high 8.8)
- [CVE-2023-41259](https://insights.sbomify.com/CVE-2023-41259/): Information disclosure in n/a (high 7.5)
- [CVE-2023-41260](https://insights.sbomify.com/CVE-2023-41260/): Information disclosure in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-18898 and fix it if it is affected.

What it is: CVE-2018-18898 is a high-severity denial of service vulnerability in Canonical Ubuntu Linux, published on 17 Mar 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-2018-18898 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-2018-18898/ (Markdown: https://insights.sbomify.com/CVE-2018-18898/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18898
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18898
- OSV: https://osv.dev/vulnerability/CVE-2018-18898

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-18898/
Summaries are generated and may contain mistakes; the official description above is the record.