# CVE-2021-25487: Samsung Mobile Devices Out-of-Bounds Read

> A buffer overflow in the modem driver allows attackers to execute arbitrary code on Samsung mobile devices via an out-of-bounds read.

- **Severity:** High 7.3 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Yes, since 29 Jun 2023 (CISA KEV)
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Oct 2021
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-4fpw-j345-q48r

## What is CVE-2021-25487?

CVE-2021-25487 is a high-severity memory corruption vulnerability in Samsung Android, published on 6 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Lack of boundary checking of a buffer in set_skb_priv() of modem interface driver prior to SMR Oct-2021 Release 1 allows OOB read and it results in arbitrary code execution by dereference of invalid function pointer.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2021-25487?

It affects 1 product.


Products: Samsung Android.

## How do I fix CVE-2021-25487?

No fix has been published for CVE-2021-25487 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 20 Jul 2023.

## Is CVE-2021-25487 being exploited?

Yes. Attackers have exploited CVE-2021-25487 in the wild since at least 29 Jun 2023.

## Other vulnerabilities in Samsung Android

- [CVE-2025-21042](https://insights.sbomify.com/CVE-2025-21042/): Samsung Mobile Devices Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2025-21043](https://insights.sbomify.com/CVE-2025-21043/): Samsung Mobile Devices Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2021-25394](https://insights.sbomify.com/CVE-2021-25394/): Samsung Mobile Devices Race Condition (medium 6.4, exploited in the wild)
- [CVE-2021-25395](https://insights.sbomify.com/CVE-2021-25395/): Samsung Mobile Devices Race Condition (medium 6.4, exploited in the wild)
- [CVE-2021-25369](https://insights.sbomify.com/CVE-2021-25369/): Samsung Mobile Devices Improper Access Control (medium 6.2, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-25487 and fix it if it is affected.

What it is: CVE-2021-25487 is a high-severity memory corruption vulnerability in Samsung Android, published on 6 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2021-25487 in the wild since at least 29 Jun 2023.

Affected product: Samsung Android. 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-2021-25487/ (Markdown: https://insights.sbomify.com/CVE-2021-25487/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25487
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25487
- OSV: https://osv.dev/vulnerability/CVE-2021-25487

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-25487/
Summaries are generated and may contain mistakes; the official description above is the record.