# CVE-2021-27610: Auth bypass in SAP NetWeaver AS ABAP and ABAP Platform

> Improper authentication in SAP NetWeaver ABAP allows malicious users to obtain illegitimate access to the system due to inconsistent RFC user information formatting.

- **Severity:** Critical 9.0 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/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:** 16 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8p63-mg7m-pg66

## What is CVE-2021-27610?

CVE-2021-27610 is a critical authentication bypass vulnerability in Sap Netweaver Application Server Abap, published on 16 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, versions - 700, 701, 702, 731, 740, 750, 751, 752, 753, 754, 755, 804, does not create information about internal and external RFC user in consistent and distinguished format, which could lead to improper authentication and may be exploited by malicious users to obtain illegitimate access to the system.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2021-27610?

It affects 2 products.


Products: Sap Netweaver Abap, Sap Netweaver Application Server Abap.

## How do I fix CVE-2021-27610?

No fix has been published for CVE-2021-27610 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27610 being exploited?

There is no known exploitation of CVE-2021-27610 in the wild and no public exploit code.

## Other vulnerabilities in Sap Netweaver Application Server Abap

- [CVE-2012-4341](https://insights.sbomify.com/CVE-2012-4341/): Memory corruption in n/a (critical 10.0)
- [CVE-2021-38178](https://insights.sbomify.com/CVE-2021-38178/): Business logic in SAP NetWeaver AS ABAP and ABAP Platform (high 8.8)
- [CVE-2022-22543](https://insights.sbomify.com/CVE-2022-22543/): Denial of service in SAP NetWeaver Application Server for ABAP (Kernel) and ABAP Platform (Kernel) (high 7.5)
- [CVE-2021-38181](https://insights.sbomify.com/CVE-2021-38181/): Denial of service in SAP NetWeaver AS ABAP and ABAP Platform (high 7.5)
- [CVE-2021-27597](https://insights.sbomify.com/CVE-2021-27597/): Denial of service in SAP NetWeaver AS for ABAP (RFC Gateway) (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27610 and fix it if it is affected.

What it is: CVE-2021-27610 is a critical authentication bypass vulnerability in Sap Netweaver Application Server Abap, published on 16 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-2021-27610 in the wild and no public exploit code.

Affected product: Sap Netweaver Application Server Abap. 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-2021-27610/ (Markdown: https://insights.sbomify.com/CVE-2021-27610/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27610
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27610
- OSV: https://osv.dev/vulnerability/CVE-2021-27610

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-27610/
Summaries are generated and may contain mistakes; the official description above is the record.