# CVE-2021-3978: Improper Preservation of Permissions in github.com/cloudflare/cfrpki/cmd/octorpki

> Local attackers can escalate privileges to root by exploiting improper file permission preservation during rsync operations in octorpki.

- **Severity:** High 7.5 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 29 Jan 2025
- **Updated:** 12 Feb 2025
- **Also known as:** DEBIAN-CVE-2021-3978, GHSA-3pqh-p72c-fj85, GO-2022-0580

## What is CVE-2021-3978?

CVE-2021-3978 is a high-severity vulnerability in Cloudflare octorpki, published on 29 Jan 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

When copying files with rsync, octorpki uses the "-a" flag 0, which forces rsync to copy binaries with the suid bit set as root. Since the provided service definition defaults to root ( https://github.com/cloudflare/cfrpki/blob/master/package/octorpki.service ) this could allow for a vector, when combined with another vulnerability that causes octorpki to process a malicious TAL file, for a local privilege escalation.

Weakness: CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2021-3978?

3 open source packages ship an affected version, including github.com/cloudflare/cfrpki. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/cloudflare/cfrpki` | Go | All versions | 1.4.2 |
| `github.com/cloudflare/cfrpki` | Go | All versions | 1.4.2 |
| `github.com/cloudflare/cfrpki` | Go | All versions | 1.4.2 |

Products: Cloudflare Octorpki.

## How do I fix CVE-2021-3978?

Upgrade github.com/cloudflare/cfrpki to 1.4.2 or later.

## Is CVE-2021-3978 being exploited?

There is no known exploitation of CVE-2021-3978 in the wild and no public exploit code.

## Other vulnerabilities in Cloudflare octorpki

- [CVE-2021-3761](https://insights.sbomify.com/CVE-2021-3761/): OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values (high 7.5)
- [CVE-2021-3907](https://insights.sbomify.com/CVE-2021-3907/): Arbitrary filepath traversal via URI injection (high 7.4)
- [CVE-2021-3908](https://insights.sbomify.com/CVE-2021-3908/): Infinite certificate chain depth results in OctoRPKI running forever (medium 5.9)
- [CVE-2022-3616](https://insights.sbomify.com/CVE-2022-3616/): OctoRPKI crash when maximum iterations number is reached (medium 5.4)
- [CVE-2021-3909](https://insights.sbomify.com/CVE-2021-3909/): Infinite open connection causes OctoRPKI to hang forever (medium 4.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3978 and fix it if it is affected.

What it is: CVE-2021-3978 is a high-severity vulnerability in Cloudflare octorpki, published on 29 Jan 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-3978 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/cloudflare/cfrpki (Go): affected all versions; fixed in 1.4.2
- github.com/cloudflare/cfrpki (Go): affected all versions; fixed in 1.4.2
- github.com/cloudflare/cfrpki (Go): affected all versions; fixed in 1.4.2

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-2021-3978/ (Markdown: https://insights.sbomify.com/CVE-2021-3978/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3978
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3978
- OSV: https://osv.dev/vulnerability/CVE-2021-3978

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3978/
Summaries are generated and may contain mistakes; the official description above is the record.