CVE-2023-21839
Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.3.0, 12.2.1.4.0 and 14.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via T3, IIOP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle WebLogic Server accessible data. CVSS 3.1 Base Score 7.5 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
- CVSS
- 7.5Highscored by the publisher (CNA)
- Exploited in the wild
- Yes, in CISA KEV since 1 May 2023CISA deadline for US federal agencies: 22 May 2023public exploit code
- EPSS
- 99.9%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 18 Jan 2023analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
- Attack surface
- Server-side
- Exploitable
- At runtime
- Attack vector
- network
- Can a WAF block it?
- No. See why
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Oracle Corporation WebLogic Server | 12.2.1.3.012.2.1.4.014.1.1.0.0Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- oracle:weblogic_server
Fix and mitigation
WAF and other mitigations
Can a WAF block it? No. The attack uses the T3 and IIOP protocols, which are not HTTP-based and thus not filterable by a web application firewall. The vulnerability allows unauthenticated network access via these protocols, so the malicious input does not come through HTTP requests.
Also consider: allow-list classes · patch
Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 1 May 2023.
- CISA due date
- 22 May 2023, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Yes: 1 Metasploit module · 8 GitHub proofs of concept · 1 Nuclei template
- CISA SSVC
- exploitation active, automatable yes, technical impact partialAssessed by CISA 17 Sept 2024 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Metasploit
- exploit/multi/iiop/cve_2023_21839_weblogic_rceexploit, rank excellent
Nuclei
- Oracle WebLogic Server - Unauthorized Accessdetection template, high
GitHub proofs of concept
- DXask88MA/Weblogic-CVE-2023-21839242 stars
- ASkyeye/CVE-2023-21839118 stars
- dinosn/CVE-2024-2093161 stars
- Firebasky/CVE-2023-2183926 stars
and 4 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 18 Jan 2023Published
- 21 Feb 2023First public exploit or proof of concept34 days later
- 1 May 2023Added to CISA KEV (exploited in the wild)69 days (about 2 months) later
- 22 May 2023CISA remediation due date (US federal agencies)21 days later
- 17 Sept 2024CISA SSVC assessment: exploitation active485 days (about 1 year) later
- 21 Oct 2025CVE record last updated399 days (about 1 year) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | NoneNo unauthorised modification. | No unauthorised modification. |
| Availability | NoneThe service stays up. | The service stays up. |
Common questions
Is CVE-2023-21839 being exploited?
Yes. CVE-2023-21839 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2023-21839?
CVE-2023-21839 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-21839?
Yes. A fix has been recorded for CVE-2023-21839. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2023-21839 affect?
CVE-2023-21839 affects oracle:weblogic_server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
3 references in the CVE record, grouped by the tags the record gives them.
Advisories (1)
- oracle.com /security-alerts/cpujan2023.html
Other links (2)
- packetstormsecurity.com /files/172882/Oracle-Weblogic-PreAuth-Remote-Command-Execution.html
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-21839
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Metasploit Framework: exploit and scanner modules
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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