# CVE-2017-5123: Privilege escalation in n/a

> Insufficient validation in the Linux kernel waitid syscall allows local attackers to escape sandboxes and escalate privileges.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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:** 2 Nov 2021
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2017-5123, GHSA-c436-43cf-26wj

## What is CVE-2017-5123?

CVE-2017-5123 is a high-severity vulnerability in Linux kernel, published on 2 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Insufficient data validation in waitid allowed an user to escape sandboxes on Linux.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-5123?

It affects 9 products.


Products: Linux kernel, Netapp Cloud Backup, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H700e Firmware, Netapp H700s Firmware.

## How do I fix CVE-2017-5123?

Apply the vendor's patch.

## Is CVE-2017-5123 being exploited?

There is no known exploitation of CVE-2017-5123 in the wild and no public exploit code.

Public exploit code:

- PoC CVE-2017-5123 - LPE - Bypassing SMEP/SMAP. No KASLR (github_poc): https://github.com/c3r34lk1ll3r/CVE-2017-5123
- Exploit for the linux kernel vulnerability CVE-2017-5123 (github_poc): https://github.com/0x5068656e6f6c/CVE-2017-5123
- Source code and configuration files related to our article in MISC96 (github_poc): https://github.com/Synacktiv-contrib/exploiting-cve-2017-5123
- linux kernel exploit   (github_poc): https://github.com/FloatingGuy/CVE-2017-5123
- Linux Kernel 4.14.0-rc4+ - 'waitid()' Local Privilege Escalation (exploitdb)
- Linux Kernel 4.13 (Ubuntu 17.10) - 'waitid()' SMEP/SMAP/Chrome Sandbox Privilege Escalation (exploitdb)

## 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-2017-5123 and fix it if it is affected.

What it is: CVE-2017-5123 is a high-severity vulnerability in Linux kernel, published on 2 Nov 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-2017-5123 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-2017-5123/ (Markdown: https://insights.sbomify.com/CVE-2017-5123/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-5123
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-5123
- OSV: https://osv.dev/vulnerability/CVE-2017-5123

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-5123/
Summaries are generated and may contain mistakes; the official description above is the record.