# CVE-2016-20024: ZKTeco ZKTime.Net 3.0.1.6 Insecure File Permissions Privilege Escalation

> Unprivileged users can escalate privileges by replacing executable files in the ZKTime.Net directory due to insecure world-writable permissions.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Mar 2026
- **Updated:** 28 Jul 2026
- **Also known as:** GHSA-5w3w-4xg4-wwhf

## What is CVE-2016-20024?

CVE-2016-20024 is a critical vulnerability in ZKTeco ZKTime.Net, published on 15 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ZKTeco ZKTime.Net 3.0.1.6 contains an insecure file permissions vulnerability that allows unprivileged users to escalate privileges by modifying executable files. Attackers can exploit world-writable permissions on the ZKTimeNet3.0 directory and its contents to replace executable files with malicious binaries for privilege escalation.

Weakness: CWE-538 (Insertion of Sensitive Information into Externally-Accessible File or Directory)

## Which versions are affected by CVE-2016-20024?


## How do I fix CVE-2016-20024?

No fix has been published for CVE-2016-20024 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-20024 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20024 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-20024 and fix it if it is affected.

What it is: CVE-2016-20024 is a critical vulnerability in ZKTeco ZKTime.Net, published on 15 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-20024 exists.

Affected product: ZKTeco ZKTime.Net. 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-2016-20024/ (Markdown: https://insights.sbomify.com/CVE-2016-20024/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-20024
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-20024
- OSV: https://osv.dev/vulnerability/CVE-2016-20024

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-20024/
Summaries are generated and may contain mistakes; the official description above is the record.