# CVE-2019-5135: Information disclosure in WAGO PFC100 Firmware

> An attacker can exploit a timing discrepancy in the WBM web application to disclose hashed user credentials on WAGO PFC controllers.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-pgq5-f878-vwpf

## What is CVE-2019-5135?

CVE-2019-5135 is a medium-severity vulnerability in WAGO PFC100 Firmware, published on 10 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An exploitable timing discrepancy vulnerability exists in the authentication functionality of the Web-Based Management (WBM) web application on WAGO PFC100/200 controllers. The WBM application makes use of the PHP crypt() function which can be exploited to disclose hashed user credentials. This affects WAGO PFC200 Firmware version 03.00.39(12) and version 03.01.07(13), and WAGO PFC100 Firmware version 03.00.39(12).

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2019-5135?

It affects 2 products.


Products: Wago Pfc100 Firmware, Wago Pfc200 Firmware.

## How do I fix CVE-2019-5135?

No fix has been published for CVE-2019-5135 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-5135 being exploited?

There is no known exploitation of CVE-2019-5135 in the wild and no public exploit code.

## Other vulnerabilities in WAGO PFC100 Firmware

- [CVE-2019-5082](https://insights.sbomify.com/CVE-2019-5082/): Memory corruption in WAGO PFC100 (critical 9.8)
- [CVE-2019-5134](https://insights.sbomify.com/CVE-2019-5134/): Auth bypass in WAGO PFC100 Firmware (high 7.5)
- [CVE-2019-5149](https://insights.sbomify.com/CVE-2019-5149/): Denial of service in WAGO PFC100 Firmware (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-5135 and fix it if it is affected.

What it is: CVE-2019-5135 is a medium-severity vulnerability in WAGO PFC100 Firmware, published on 10 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-5135 in the wild and no public exploit code.

Affected product: WAGO PFC100 Firmware. 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-2019-5135/ (Markdown: https://insights.sbomify.com/CVE-2019-5135/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-5135
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-5135
- OSV: https://osv.dev/vulnerability/CVE-2019-5135

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-5135/
Summaries are generated and may contain mistakes; the official description above is the record.