# CVE-2020-14310: Integer overflow in grub2

> An integer overflow in GRUB2 allows attackers to trigger a heap buffer overflow via a malicious font file, potentially leading to code execution and privilege escalation.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Jul 2020
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2020-14310, AZL-6458, DEBIAN-CVE-2020-14310, GHSA-849w-6cw8-9p7m, UBUNTU-CVE-2020-14310

## What is CVE-2020-14310?

CVE-2020-14310 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 31 Jul 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

There is an issue on grub2 before version 2.06 at function read_section_as_string(). It expects a font name to be at max UINT32_MAX - 1 length in bytes but it doesn't verify it before proceed with buffer allocation to read the value from the font value. An attacker may leverage that by crafting a malicious font file which has a name with UINT32_MAX, leading to read_section_as_string() to an arithmetic overflow, zero-sized allocation and further heap-based buffer overflow.

Weakness: CWE-190 (Integer Overflow or Wraparound), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2020-14310?

It affects 7 products.


Products: Canonical Ubuntu Linux, Gnu Grub2, Opensuse Leap, Redhat Enterprise Linux, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Tus.

## How do I fix CVE-2020-14310?

Upgrade to a fixed version.

## Is CVE-2020-14310 being exploited?

There is no known exploitation of CVE-2020-14310 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-14310 and fix it if it is affected.

What it is: CVE-2020-14310 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 31 Jul 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-2020-14310 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-2020-14310/ (Markdown: https://insights.sbomify.com/CVE-2020-14310/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-14310
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-14310
- OSV: https://osv.dev/vulnerability/CVE-2020-14310

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-14310/
Summaries are generated and may contain mistakes; the official description above is the record.