# CVE-2019-18684: Race condition in n/a

> Local attackers can exploit a race condition in Sudo to escalate privileges to root by manipulating file descriptors during password prompts.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Nov 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-h9q8-53pc-hhxf

## What is CVE-2019-18684?

CVE-2019-18684 is a high-severity vulnerability in n/a, published on 4 Nov 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process. This occurs because of a race condition between determining a uid, and the setresuid and openat system calls. The attacker can write "ALL ALL=(ALL) NOPASSWD:ALL" to /proc/#####/fd/3 at a time when Sudo is prompting for a password. NOTE: This has been disputed due to the way Linux /proc works. It has been argued that writing to /proc/#####/fd/3 would only be viable if you had permission to write to /etc/sudoers. Even with write permission to /proc/#####/fd/3, it would not help you write to /etc/sudoers

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2019-18684?

It affects 1 product.


Products: Sudo Project Sudo.

## How do I fix CVE-2019-18684?

No fix has been published for CVE-2019-18684 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-18684 being exploited?

There is no known exploitation of CVE-2019-18684 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2017-1000368](https://insights.sbomify.com/CVE-2017-1000368/): Command injection in n/a (high 8.2)
- [CVE-2015-5602](https://insights.sbomify.com/CVE-2015-5602/): Privilege escalation in n/a (high 7.2)
- [CVE-2022-43995](https://insights.sbomify.com/CVE-2022-43995/): Memory corruption in n/a (high 7.1)
- [CVE-2023-42465](https://insights.sbomify.com/CVE-2023-42465/): Privilege escalation in n/a (high 7.0)
- [CVE-2015-8239](https://insights.sbomify.com/CVE-2015-8239/): Race condition in n/a (high 7.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-18684 and fix it if it is affected.

What it is: CVE-2019-18684 is a high-severity vulnerability in n/a, published on 4 Nov 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-18684 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-2019-18684/ (Markdown: https://insights.sbomify.com/CVE-2019-18684/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18684
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18684
- OSV: https://osv.dev/vulnerability/CVE-2019-18684

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-18684/
Summaries are generated and may contain mistakes; the official description above is the record.