# CVE-2021-30129: DoS/OOM leak vulnerability in Apache Mina SSHD Server

> An attacker can cause an OutOfMemory error in Apache Mina SSHD, leading to a denial of service, by exploiting SFTP or port forwarding features.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jul 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-9279-7hph-r3xw, MINI-5cpm-q7xg-fg6g, OESA-2021-1312

## What is CVE-2021-30129?

CVE-2021-30129 is a medium-severity denial of service vulnerability in Oracle Flexcube Universal Banking, published on 12 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in sshd-core of Apache Mina SSHD allows an attacker to overflow the server causing an OutOfMemory error. This issue affects the SFTP and port forwarding features of Apache Mina SSHD version 2.0.0 and later versions. It was addressed in Apache Mina SSHD 2.7.0

Weakness: CWE-772 (Missing Release of Resource after Effective Lifetime)

## Which versions are affected by CVE-2021-30129?

4 open source packages ship an affected version, including org.apache.sshd:sshd-core and org.apache.sshd:sshd-mina. It affects 9 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.sshd:sshd-core` | Maven | From 2.0.0 | 2.7.0 |
| `org.apache.sshd:sshd-core` | Maven | From 2.0.0 | 2.7.0 |
| `org.apache.sshd:sshd-mina` | Maven | From 2.0.0 | 2.7.0 |
| `org.apache.sshd:sshd-mina` | Maven | From 2.0.0 | 2.7.0 |

Products: Apache Sshd, Oracle Banking Payments, Oracle Banking Trade Finance, Oracle Banking Treasury Management, Oracle Communications Cloud Native Core Console, Oracle Flexcube Universal Banking, Oracle Middleware Common Libraries and Tools, Oracle Oss Support Tools, Oracle Retail Customer Management and Segmentation Foundation.

## How do I fix CVE-2021-30129?

Upgrade org.apache.sshd:sshd-core to 2.7.0 or later.

## Is CVE-2021-30129 being exploited?

There is no known exploitation of CVE-2021-30129 in the wild and no public exploit code.

## Other vulnerabilities in Oracle Flexcube Universal Banking

- [CVE-2022-45047](https://insights.sbomify.com/CVE-2022-45047/): Apache MINA SSHD: Java unsafe deserialization vulnerability (critical 9.8)
- [CVE-2023-35887](https://insights.sbomify.com/CVE-2023-35887/): Apache MINA SSHD: Information disclosure bugs with RootedFilesystem (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-30129 and fix it if it is affected.

What it is: CVE-2021-30129 is a medium-severity denial of service vulnerability in Oracle Flexcube Universal Banking, published on 12 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-30129 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.sshd:sshd-core (Maven): affected from 2.0.0; fixed in 2.7.0
- org.apache.sshd:sshd-core (Maven): affected from 2.0.0; fixed in 2.7.0
- org.apache.sshd:sshd-mina (Maven): affected from 2.0.0; fixed in 2.7.0
- org.apache.sshd:sshd-mina (Maven): affected from 2.0.0; fixed in 2.7.0

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-2021-30129/ (Markdown: https://insights.sbomify.com/CVE-2021-30129/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-30129
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-30129
- OSV: https://osv.dev/vulnerability/CVE-2021-30129

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-30129/
Summaries are generated and may contain mistakes; the official description above is the record.