# CVE-2018-1113: Auth bypass in setup

> Adding nologin to /etc/shells allows users with that shell to bypass authentication checks in daemons relying on pam_shells.

- **Severity:** Medium 4.8 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 2 Jul 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-pj9f-pvw9-ffjc, RHSA-2018:3249

## What is CVE-2018-1113?

CVE-2018-1113 is a medium-severity authentication bypass vulnerability in Redhat Enterprise Linux Desktop, published on 2 Jul 2018. 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

setup before version 2.11.4-1.fc28 in Fedora and Red Hat Enterprise Linux added /sbin/nologin and /usr/sbin/nologin to /etc/shells. This violates security assumptions made by pam_shells and some daemons which allow access based on a user's shell being listed in /etc/shells. Under some circumstances, users which had their shell changed to /sbin/nologin could still access the system.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2018-1113?

It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `setup` | Red Hat:enterprise_linux:7::client | All versions | 0:2.8.71-10.el7 |
| `setup` | Red Hat:enterprise_linux:7::computenode | All versions | 0:2.8.71-10.el7 |
| `setup` | Red Hat:enterprise_linux:7::server | All versions | 0:2.8.71-10.el7 |
| `setup` | Red Hat:enterprise_linux:7::workstation | All versions | 0:2.8.71-10.el7 |

Products: Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Server, Redhat Enterprise Linux Workstation, Redhat Setup.

## How do I fix CVE-2018-1113?

Apply the vendor's patch.

## Is CVE-2018-1113 being exploited?

There is no known exploitation of CVE-2018-1113 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux Desktop

- [CVE-2016-5405](https://insights.sbomify.com/CVE-2016-5405/): Information disclosure in n/a (critical 9.8)
- [CVE-2016-7050](https://insights.sbomify.com/CVE-2016-7050/): Deserialization in n/a (critical 9.8)
- [CVE-2014-8241](https://insights.sbomify.com/CVE-2014-8241/): Null dereference in n/a (critical 9.8)
- [CVE-2014-8567](https://insights.sbomify.com/CVE-2014-8567/): Denial of service in n/a (critical 9.4)
- [CVE-2018-10897](https://insights.sbomify.com/CVE-2018-10897/): Path traversal in yum-utils: (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1113 and fix it if it is affected.

What it is: CVE-2018-1113 is a medium-severity authentication bypass vulnerability in Redhat Enterprise Linux Desktop, published on 2 Jul 2018. 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-2018-1113 in the wild and no public exploit code.

Affected product: Redhat Enterprise Linux Desktop. 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-2018-1113/ (Markdown: https://insights.sbomify.com/CVE-2018-1113/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1113
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1113
- OSV: https://osv.dev/vulnerability/CVE-2018-1113

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1113/
Summaries are generated and may contain mistakes; the official description above is the record.