# CVE-2021-26917: Path traversal in n/a

> Attackers can write screen captures to arbitrary directories via a crafted API notification path in PyBitmessage.

- **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:** No
- **Published:** 8 Feb 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-j9hf-937w-gvx5

## What is CVE-2021-26917?

CVE-2021-26917 is a medium-severity path traversal vulnerability in n/a, published on 8 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

PyBitmessage through 0.6.3.2 allows attackers to write screen captures to Potentially Unwanted Directories via a crafted apinotifypath value. NOTE: the discoverer states "security mitigation may not be necessary as there is no evidence yet that these screen intercepts are actually transported away from the local host." NOTE: it is unclear whether there are any common use cases in which apinotifypath is controlled by an attacker

## Which versions are affected by CVE-2021-26917?

It affects 1 product.


Products: Bitmessage Pybitmessage.

## How do I fix CVE-2021-26917?

No fix has been published for CVE-2021-26917 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-26917 being exploited?

There is no known exploitation of CVE-2021-26917 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-1000070](https://insights.sbomify.com/CVE-2018-1000070/): Code injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26917 and fix it if it is affected.

What it is: CVE-2021-26917 is a medium-severity path traversal vulnerability in n/a, published on 8 Feb 2021. 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-2021-26917 in the wild and no public exploit code.

Affected product: n/a. 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-2021-26917/ (Markdown: https://insights.sbomify.com/CVE-2021-26917/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26917
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26917
- OSV: https://osv.dev/vulnerability/CVE-2021-26917

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26917/
Summaries are generated and may contain mistakes; the official description above is the record.