# CVE-2023-40185: Shescape on Windows escaping may be bypassed in threaded context

> Attackers can bypass shell escaping in threaded Windows contexts, potentially leading to command injection if the wrong shell is used.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Aug 2023
- **Updated:** 30 Sep 2024
- **Also known as:** GHSA-j55r-787p-m549

## What is CVE-2023-40185?

CVE-2023-40185 is a medium-severity command injection vulnerability in ericcornelissen shescape, published on 23 Aug 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

shescape is simple shell escape library for JavaScript. This may impact users that use Shescape on Windows in a threaded context. The vulnerability can result in Shescape escaping (or quoting) for the wrong shell, thus allowing attackers to bypass protections depending on the combination of expected and used shell. This bug has been patched in version 1.7.4.

Weakness: CWE-150 (Improper Neutralization of Escape, Meta, or Control Sequences)

## Which versions are affected by CVE-2023-40185?

2 open source packages ship an affected version, including shescape. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `shescape` | npm | All versions | 1.7.4 |
| `shescape` | npm | All versions | 1.7.4 |

Products: Shescape Project Shescape.

## How do I fix CVE-2023-40185?

Upgrade shescape to 1.7.4 or later.

## Is CVE-2023-40185 being exploited?

There is no known exploitation of CVE-2023-40185 in the wild and no public exploit code.

## Other vulnerabilities in ericcornelissen shescape

- [CVE-2022-31180](https://insights.sbomify.com/CVE-2022-31180/): Insufficient escaping of whitespace in shescape (critical 9.8)
- [CVE-2022-31179](https://insights.sbomify.com/CVE-2022-31179/): Insufficient escaping of line feeds for CMD in shescape (high 8.1)
- [CVE-2026-32094](https://insights.sbomify.com/CVE-2026-32094/): Shescape escape() leaves bracket glob expansion active on Bash, BusyBox, and Dash (medium 6.9)
- [CVE-2021-21384](https://insights.sbomify.com/CVE-2021-21384/): Null characters not escaped in shescape (medium 6.3)
- [CVE-2022-24725](https://insights.sbomify.com/CVE-2022-24725/): Exposure of home directory through shescape on Unix with Bash (medium 6.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-40185 and fix it if it is affected.

What it is: CVE-2023-40185 is a medium-severity command injection vulnerability in ericcornelissen shescape, published on 23 Aug 2023. 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-2023-40185 in the wild and no public exploit code.

Affected packages and fixed versions:
- shescape (npm): affected all versions; fixed in 1.7.4
- shescape (npm): affected all versions; fixed in 1.7.4

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-2023-40185/ (Markdown: https://insights.sbomify.com/CVE-2023-40185/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40185
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40185
- OSV: https://osv.dev/vulnerability/CVE-2023-40185

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40185/
Summaries are generated and may contain mistakes; the official description above is the record.