# CVE-2021-42029: Missing authorization in SIMATIC STEP 7 (TIA Portal) V15

> An attacker with direct access to the web server can escalate privileges due to improper access control in Siemens TIA Portal engineering software.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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:** No
- **Published:** 12 Apr 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-vp88-r9qc-vwrw

## What is CVE-2021-42029?

CVE-2021-42029 is a high-severity missing authorization vulnerability in Siemens SIMATIC STEP 7 (TIA Portal) V15, published on 12 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability has been identified in SIMATIC STEP 7 (TIA Portal) V15 (All versions), SIMATIC STEP 7 (TIA Portal) V16 (All versions < V16 Update 5), SIMATIC STEP 7 (TIA Portal) V17 (All versions < V17 Update 2). An attacker could achieve privilege escalation on the web server of certain devices due to improper access control vulnerability in the engineering system software. The attacker needs to have direct access to the impacted web server.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2021-42029?

It affects 1 product.


Products: Siemens Simatic Step 7.

## How do I fix CVE-2021-42029?

No fix has been published for CVE-2021-42029 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42029 being exploited?

There is no known exploitation of CVE-2021-42029 in the wild and no public exploit code.

## Other vulnerabilities in Siemens SIMATIC STEP 7 (TIA Portal) V15

- [CVE-2015-1601](https://insights.sbomify.com/CVE-2015-1601/): Other in n/a (medium 6.8)
- [CVE-2016-7959](https://insights.sbomify.com/CVE-2016-7959/): Information disclosure in n/a (medium 4.7)
- [CVE-2015-1356](https://insights.sbomify.com/CVE-2015-1356/): Auth bypass in n/a (medium 4.4)
- [CVE-2022-46141](https://insights.sbomify.com/CVE-2022-46141/): Information disclosure in SIMATIC STEP 7 (TIA Portal) (medium 4.2)
- [CVE-2016-7960](https://insights.sbomify.com/CVE-2016-7960/): Information disclosure in n/a (low 2.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42029 and fix it if it is affected.

What it is: CVE-2021-42029 is a high-severity missing authorization vulnerability in Siemens SIMATIC STEP 7 (TIA Portal) V15, published on 12 Apr 2022. 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-2021-42029 in the wild and no public exploit code.

Affected product: Siemens SIMATIC STEP 7 (TIA Portal) V15. 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-2021-42029/ (Markdown: https://insights.sbomify.com/CVE-2021-42029/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42029
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42029
- OSV: https://osv.dev/vulnerability/CVE-2021-42029

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-42029/
Summaries are generated and may contain mistakes; the official description above is the record.