# CVE-2019-8721: Code injection in Xcode

> An attacker can execute arbitrary code with user privileges by exploiting improper input validation in the Xcode linker during compilation.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 18 Dec 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-m438-rqxw-r97m

## What is CVE-2019-8721?

CVE-2019-8721 is a high-severity code injection vulnerability in Apple Xcode, published on 18 Dec 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Multiple issues in ld64 in the Xcode toolchains were addressed by updating to version ld64-507.4. This issue is fixed in Xcode 11.0. Compiling code without proper input validation could lead to arbitrary code execution with user privilege.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2019-8721?

It affects 1 product.


Products: Apple Xcode.

## How do I fix CVE-2019-8721?

No fix has been published for CVE-2019-8721 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-8721 being exploited?

There is no known exploitation of CVE-2019-8721 in the wild and no public exploit code.

## Other vulnerabilities in Apple Xcode

- [CVE-2025-48384](https://insights.sbomify.com/CVE-2025-48384/): Git Link Following (high 8.1, exploited in the wild)
- [CVE-2014-9390](https://insights.sbomify.com/CVE-2014-9390/): JGit Improper Input Validation vulnerability (critical 9.8)
- [CVE-2019-14379](https://insights.sbomify.com/CVE-2019-14379/): Deserialization of untrusted data in FasterXML jackson-databind (critical 9.8)
- [CVE-2018-4164](https://insights.sbomify.com/CVE-2018-4164/): An issue was discovered in certain Apple products. (critical 9.8)
- [CVE-2016-0746](https://insights.sbomify.com/CVE-2016-0746/): Use after free in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-8721 and fix it if it is affected.

What it is: CVE-2019-8721 is a high-severity code injection vulnerability in Apple Xcode, published on 18 Dec 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-8721 in the wild and no public exploit code.

Affected product: Apple Xcode. 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-2019-8721/ (Markdown: https://insights.sbomify.com/CVE-2019-8721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-8721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-8721
- OSV: https://osv.dev/vulnerability/CVE-2019-8721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-8721/
Summaries are generated and may contain mistakes; the official description above is the record.