# CVE-2021-47269: usb: dwc3: ep0: fix NULL pointer exception

> A missing index validation in the Linux kernel DWC3 USB driver allows a local attacker to trigger a NULL pointer dereference, causing a system crash.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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:** 21 May 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47269, GHSA-qp63-w47q-g9vj, UBUNTU-CVE-2021-47269

## What is CVE-2021-47269?

CVE-2021-47269 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

usb: dwc3: ep0: fix NULL pointer exception

There is no validation of the index from dwc3_wIndex_to_dep() and we might
be referring a non-existing ep and trigger a NULL pointer exception. In
certain configurations we might use fewer eps and the index might wrongly
indicate a larger ep index than existing.

By adding this validation from the patch we can actually report a wrong
index back to the caller.

In our usecase we are using a composite device on an older kernel, but
upstream might use this fix also. Unfortunately, I cannot describe the
hardware for others to reproduce the issue as it is a proprietary
implementation.

[   82.958261] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a4
[   82.966891] Mem abort info:
[   82.969663]   ESR = 0x96000006
[   82.972703]   Exception class = DABT (current EL), IL = 32 bits
[   82.978603]   SET = 0, FnV = 0
[   82.981642]   EA = 0, S1PTW = 0
[   82.984765] Data abort info:
[   82.987631]   ISV = 0, ISS = 0x00000006
[   82.991449]   CM = 0, WnR = 0
[   82.994409] user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c6210ccc
[   83.000999] [00000000000000a4] pgd=0000000053aa5003, pud=0000000053aa5003, pmd=0000000000000000
[   83.009685] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[   83.026433] Process irq/62-dwc3 (pid: 303, stack limit = 0x000000003985154c)
[   83.033470] CPU: 0 PID: 303 Comm: irq/62-dwc3 Not tainted 4.19.124 #1
[   83.044836] pstate: 60000085 (nZCv daIf -PAN -UAO)
[   83.049628] pc : dwc3_ep0_handle_feature+0x414/0x43c
[   83.054558] lr : dwc3_ep0_interrupt+0x3b4/0xc94

...

[   83.141788] Call trace:
[   83.144227]  dwc3_ep0_handle_feature+0x414/0x43c
[   83.148823]  dwc3_ep0_interrupt+0x3b4/0xc94
[   83.181546] ---[ end trace aac6b5267d84c32f ]---

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-47269?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47269?

Apply the vendor's patch.

## Is CVE-2021-47269 being exploited?

There is no known exploitation of CVE-2021-47269 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47269 and fix it if it is affected.

What it is: CVE-2021-47269 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. 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-2021-47269 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2021-47269/ (Markdown: https://insights.sbomify.com/CVE-2021-47269/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47269
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47269
- OSV: https://osv.dev/vulnerability/CVE-2021-47269

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47269/
Summaries are generated and may contain mistakes; the official description above is the record.