# CVE-2020-15704: pppd arbitrary file read information disclosure vulnerability

> A local non-root attacker can exploit the MODPROBE_OPTIONS environment variable in pppd to read arbitrary root files, leading to information disclosure.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **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:** 31 Aug 2020
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-2q4h-xfv6-4848, UBUNTU-CVE-2020-15704, USN-4451-1, USN-4451-2

## What is CVE-2020-15704?

CVE-2020-15704 is a medium-severity vulnerability in Canonical ppp, published on 31 Aug 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The modprobe child process in the ./debian/patches/load_ppp_generic_if_needed patch file incorrectly handled module loading. A local non-root attacker could exploit the MODPROBE_OPTIONS environment variable to read arbitrary root files. Fixed in 2.4.5-5ubuntu1.4, 2.4.5-5.1ubuntu2.3+esm2, 2.4.7-1+2ubuntu1.16.04.3, 2.4.7-2+2ubuntu1.3, 2.4.7-2+4.1ubuntu5.1, 2.4.7-2+4.1ubuntu6. Was ZDI-CAN-11504.

Weakness: CWE-20 (Improper Input Validation), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2020-15704?

It affects 1 product.


Products: Canonical Ppp.

## How do I fix CVE-2020-15704?

Apply the vendor's patch.

## Is CVE-2020-15704 being exploited?

There is no known exploitation of CVE-2020-15704 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-15704 and fix it if it is affected.

What it is: CVE-2020-15704 is a medium-severity vulnerability in Canonical ppp, published on 31 Aug 2020. 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-2020-15704 in the wild and no public exploit code.

Affected product: Canonical ppp. 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-2020-15704/ (Markdown: https://insights.sbomify.com/CVE-2020-15704/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-15704
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-15704
- OSV: https://osv.dev/vulnerability/CVE-2020-15704

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-15704/
Summaries are generated and may contain mistakes; the official description above is the record.