# CVE-2021-27607: Null dereference in SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher)

> An unauthenticated attacker can crash the SAP NetWeaver ABAP Server by sending a specially crafted packet, causing a denial of service.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 9 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8442-3jhx-m6j3

## What is CVE-2021-27607?

CVE-2021-27607 is a high-severity vulnerability in SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher), published on 9 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher), versions - KRNL32NUC - 7.22,7.22EXT, KRNL32UC - 7.22,7.22EXT, KRNL64NUC - 7.22,7.22EXT,7.49, KRNL64UC - 8.04,7.22,7.22EXT,7.49,7.53,7.73, KERNEL - 7.22,8.04,7.49,7.53,7.73,7.77,7.81,7.82,7.83, allows an unauthenticated attacker without specific knowledge of the system to send a specially crafted packet over a network which will trigger an internal error in the system due to improper input validation in method ThSncIn() causing the system to crash and rendering it unavailable. In this attack, no data in the system can be viewed or modified.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-27607?

It affects 1 product.


Products: Sap Netweaver as Abap.

## How do I fix CVE-2021-27607?

No fix has been published for CVE-2021-27607 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27607 being exploited?

There is no known exploitation of CVE-2021-27607 in the wild and no public exploit code.

## Other vulnerabilities in SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher)

- [CVE-2022-27668](https://insights.sbomify.com/CVE-2022-27668/): Missing authorization in SAP NetWeaver and ABAP Platform (critical 9.8)
- [CVE-2021-27606](https://insights.sbomify.com/CVE-2021-27606/): Denial of service in SAP NetWeaver ABAP Server and ABAP Platform (Enqueue Server) (high 7.5)
- [CVE-2021-27628](https://insights.sbomify.com/CVE-2021-27628/): Memory corruption in SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher) (high 7.5)
- [CVE-2021-27629](https://insights.sbomify.com/CVE-2021-27629/): Denial of service in SAP NetWeaver ABAP Server and ABAP Platform (Enqueue Server) (high 7.5)
- [CVE-2021-27630](https://insights.sbomify.com/CVE-2021-27630/): Null dereference in SAP NetWeaver ABAP Server and ABAP Platform (Enqueue Server) (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27607 and fix it if it is affected.

What it is: CVE-2021-27607 is a high-severity vulnerability in SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher), published on 9 Jun 2021. 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-2021-27607 in the wild and no public exploit code.

Affected product: SAP NetWeaver ABAP Server and ABAP Platform (Dispatcher). 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-2021-27607/ (Markdown: https://insights.sbomify.com/CVE-2021-27607/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27607
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27607
- OSV: https://osv.dev/vulnerability/CVE-2021-27607

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27607/
Summaries are generated and may contain mistakes; the official description above is the record.