# CVE-2023-29827: Code injection in n/a

> Server-side template injection in EJS allows code execution if the closeDelimiter parameter is controlled by untrusted input.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 May 2023
- **Updated:** 29 Jan 2025
- **Also known as:** DEBIAN-CVE-2023-29827, GHSA-j5pp-6f4w-r5r6

## What is CVE-2023-29827?

CVE-2023-29827 is a critical code injection vulnerability in n/a, published on 4 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ejs v3.1.9 is vulnerable to server-side template injection. If the ejs file is controllable, template injection can be implemented through the configuration settings of the closeDelimiter parameter. NOTE: this is disputed by the vendor because the render function is not intended to be used with untrusted input.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2023-29827?

It affects 1 product.


Products: Ejs Ejs.

## How do I fix CVE-2023-29827?

No fix has been published for CVE-2023-29827 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-29827 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-29827 exists.

Public exploit code:

- Embedded JavaScript(EJS) 3.1.6 - Template Injection (nuclei): http/cves/2023/CVE-2023-29827.yaml

## Other vulnerabilities in n/a

- [CVE-2022-29078](https://insights.sbomify.com/CVE-2022-29078/): ejs template injection vulnerability (critical 9.8)
- [CVE-2017-1000228](https://insights.sbomify.com/CVE-2017-1000228/): ejs is vulnerable to remote code execution due to weak input validation (critical 9.8)
- [CVE-2017-1000189](https://insights.sbomify.com/CVE-2017-1000189/): ejs vulnerable to DoS due to weak input validation (high 7.5)
- [CVE-2017-1000188](https://insights.sbomify.com/CVE-2017-1000188/): mde ejs vulnerable to XSS (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-29827 and fix it if it is affected.

What it is: CVE-2023-29827 is a critical code injection vulnerability in n/a, published on 4 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-29827 exists.

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-2023-29827/ (Markdown: https://insights.sbomify.com/CVE-2023-29827/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-29827
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-29827
- OSV: https://osv.dev/vulnerability/CVE-2023-29827

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-29827/
Summaries are generated and may contain mistakes; the official description above is the record.