# CVE-2020-8648: Use after free in n/a

> A use-after-free flaw in the Linux kernel TTY driver allows local attackers to execute arbitrary code or escalate privileges.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:** Yes
- **Published:** 6 Feb 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-8648, GHSA-9hr4-45xh-6xvh, UBUNTU-CVE-2020-8648

## What is CVE-2020-8648?

CVE-2020-8648 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 6 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

There is a use-after-free vulnerability in the Linux kernel through 5.5.2 in the n_tty_receive_buf_common function in drivers/tty/n_tty.c.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-8648?

It affects 9 products.


Products: Broadcom Brocade Fabric Operating System Firmware, Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel, Netapp Active Iq Unified Manager, Netapp Cloud Backup, Netapp Hci Baseboard Management Controller, Netapp Solidfire Baseboard Management Controller, Opensuse Leap.

## How do I fix CVE-2020-8648?

Apply the vendor's patch.

## Is CVE-2020-8648 being exploited?

There is no known exploitation of CVE-2020-8648 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2023-27534](https://insights.sbomify.com/CVE-2023-27534/): Path traversal in https://github.com/curl/curl (high 8.8)
- [CVE-2021-4197](https://insights.sbomify.com/CVE-2021-4197/): Privilege escalation in kernel (high 7.8)
- [CVE-2023-27538](https://insights.sbomify.com/CVE-2023-27538/): Auth bypass in https://github.com/curl/curl (high 7.7)
- [CVE-2021-27218](https://insights.sbomify.com/CVE-2021-27218/): Integer overflow in n/a (high 7.5)
- [CVE-2021-27219](https://insights.sbomify.com/CVE-2021-27219/): Integer overflow in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8648 and fix it if it is affected.

What it is: CVE-2020-8648 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 6 Feb 2020. 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-2020-8648 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-2020-8648/ (Markdown: https://insights.sbomify.com/CVE-2020-8648/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8648
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8648
- OSV: https://osv.dev/vulnerability/CVE-2020-8648

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8648/
Summaries are generated and may contain mistakes; the official description above is the record.