# CVE-2020-2551: Oracle Fusion Middleware Unspecified

> Unauthenticated attackers can achieve remote code execution and full server takeover via IIOP deserialization flaws in Oracle WebLogic Server.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 16 Nov 2023 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jan 2020
- **Updated:** 12 Jan 2026
- **Also known as:** GHSA-85qx-3cmc-hcq4

## What is CVE-2020-2551?

CVE-2020-2551 is a critical unsafe deserialization vulnerability in Oracle Weblogic Server, published on 15 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: WLS Core Components). Supported versions that are affected are 10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0 and 12.2.1.4.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via IIOP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in takeover of Oracle WebLogic Server. CVSS 3.0 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

## Which versions are affected by CVE-2020-2551?

It affects 1 product.


Products: Oracle Weblogic Server.

## How do I fix CVE-2020-2551?

No fix has been published for CVE-2020-2551 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 7 Dec 2023.

## Is CVE-2020-2551 being exploited?

Yes. Attackers have exploited CVE-2020-2551 in the wild since at least 16 Nov 2023.

Public exploit code:

- weblogic 漏洞扫描工具。目前包含对以下漏洞的检测能力：CVE-2014-4210、CVE-2016-0638、CVE-2016-3510、CVE-2017-3248、CVE-2017-3506、CVE-2017-10271、CVE-2018-2628、CVE-2018-2893、CVE-2018-2894、CVE-2018-3191、CVE-2018-3245、CVE-2018-3252、CVE-2019-2618、CVE-2019-2725、CVE-2019-2729、CVE-2019-2890、CVE-2020-2551、CVE-2020-14750、CVE-2020-14882、CVE-2020-14883 (github_poc): https://github.com/daybreak-kits/weblogicScanner
- Weblogic IIOP CVE-2020-2551 (github_poc): https://github.com/Y4er/CVE-2020-2551
- how detect CVE-2020-2551 poc exploit python Weblogic RCE with IIOP (github_poc): https://github.com/hktalent/CVE-2020-2551
- Weblogic Vuln POC  EXP cve-2020-2551 cve-2020-2555 cve-2020-2883 ，。。。 (github_poc): https://github.com/zzwlpx/weblogicPoc
- Weblogic RCE with IIOP (github_poc): https://github.com/jas502n/CVE-2020-2551
- CVE-2020-2551 POC to use in Internet (github_poc): https://github.com/Dido1960/Weblogic-CVE-2020-2551-To-Internet

## Other vulnerabilities in Oracle Weblogic Server

- [CVE-2020-14750](https://insights.sbomify.com/CVE-2020-14750/): Oracle WebLogic Server Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2020-14882](https://insights.sbomify.com/CVE-2020-14882/): Oracle WebLogic Server Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2020-14644](https://insights.sbomify.com/CVE-2020-14644/): Oracle WebLogic Server Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2020-2883](https://insights.sbomify.com/CVE-2020-2883/): Oracle WebLogic Server Unspecified (critical 9.8, exploited in the wild)
- [CVE-2018-2628](https://insights.sbomify.com/CVE-2018-2628/): Oracle WebLogic Server Unspecified (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-2551 and fix it if it is affected.

What it is: CVE-2020-2551 is a critical unsafe deserialization vulnerability in Oracle Weblogic Server, published on 15 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-2551 in the wild since at least 16 Nov 2023.

Affected product: Oracle Weblogic Server. 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-2020-2551/ (Markdown: https://insights.sbomify.com/CVE-2020-2551/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-2551
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-2551
- OSV: https://osv.dev/vulnerability/CVE-2020-2551

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-2551/
Summaries are generated and may contain mistakes; the official description above is the record.