# CVE-2020-35508: Race condition in kernel

> A local attacker can exploit a race condition in Linux kernel signal handling to bypass security checks and send signals to privileged processes.

- **Severity:** Medium 4.5 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L`)
- **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:** 26 Mar 2021
- **Updated:** 4 Aug 2024
- **Also known as:** AZL-6528, DEBIAN-CVE-2020-35508, GHSA-467m-6jmp-65g9, UBUNTU-CVE-2020-35508

## What is CVE-2020-35508?

CVE-2020-35508 is a medium-severity vulnerability in Linux kernel, published on 26 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw possibility of race condition and incorrect initialization of the process id was found in the Linux kernel child/parent process identification handling while filtering signal handlers. A local attacker is able to abuse this flaw to bypass checks to send any signal to a privileged process.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-665 (Improper Initialization)

## Which versions are affected by CVE-2020-35508?

It affects 18 products.


Products: Linux kernel, Netapp A700s Firmware, Netapp Aff A400 Firmware, Netapp Brocade Fabric Operating System Firmware, Netapp Fas8300 Firmware, Netapp Fas8700 Firmware, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H610c Firmware, Netapp H610s Firmware, Netapp H615c Firmware, Netapp H700e Firmware, Netapp H700s Firmware, Redhat Enterprise Linux.

## How do I fix CVE-2020-35508?

Apply the vendor's patch.

## Is CVE-2020-35508 being exploited?

There is no known exploitation of CVE-2020-35508 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-2020-35508 and fix it if it is affected.

What it is: CVE-2020-35508 is a medium-severity vulnerability in Linux kernel, published on 26 Mar 2021. 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-2020-35508 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-2020-35508/ (Markdown: https://insights.sbomify.com/CVE-2020-35508/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-35508
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-35508
- OSV: https://osv.dev/vulnerability/CVE-2020-35508

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-35508/
Summaries are generated and may contain mistakes; the official description above is the record.