# CVE-2021-21479: Remote Code Execution in SCIMono

> Attackers can inject and execute Java expressions in SCIMono, compromising system integrity and availability.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Feb 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-29q4-gxjq-rx5c

## What is CVE-2021-21479?

CVE-2021-21479 is a high-severity code injection vulnerability in SAP SE SCIMono, published on 9 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

In SCIMono before 0.0.19, it is possible for an attacker to inject and execute java expression compromising the availability and integrity of the system.

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

## Which versions are affected by CVE-2021-21479?

2 open source packages ship an affected version, including com.sap.scimono:scimono-server. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.sap.scimono:scimono-server` | Maven | All versions | 0.0.19 |
| `com.sap.scimono:scimono-server` | Maven | All versions | 0.0.19 |

Products: Sap Scimono.

## How do I fix CVE-2021-21479?

Upgrade com.sap.scimono:scimono-server to 0.0.19 or later.

## Is CVE-2021-21479 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21479 exists.

Public exploit code:

- SCIMono <0.0.19 - Remote Code Execution (nuclei): http/cves/2021/CVE-2021-21479.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21479 and fix it if it is affected.

What it is: CVE-2021-21479 is a high-severity code injection vulnerability in SAP SE SCIMono, published on 9 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21479 exists.

Affected packages and fixed versions:
- com.sap.scimono:scimono-server (Maven): affected all versions; fixed in 0.0.19
- com.sap.scimono:scimono-server (Maven): affected all versions; fixed in 0.0.19

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-2021-21479/ (Markdown: https://insights.sbomify.com/CVE-2021-21479/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21479
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21479
- OSV: https://osv.dev/vulnerability/CVE-2021-21479

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21479/
Summaries are generated and may contain mistakes; the official description above is the record.