CVE-2023-21839VulnerabilityPublished 17 Jan 2023Updated 21 Oct 2025

CVE-2023-21839: Oracle WebLogic Server · Missing Authentication

Affects Oracle WebLogic ServerSource CVE Database V5

Exploited in the wild · KEV due 22 May 2023 · public exploit available (Metasploit) · 99% EPSS : apply the vendor's fix or mitigations to Oracle WebLogic Server now.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

KEV deadline: 22 May 2023 US federal agencies must patch by this date; a sensible deadline for everyone else.
EPSS: 99.9% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 17 Jan 2023
Detectable: evidence found.
nuclei template: Oracle WebLogic Server - Unauthorized Access
Weaponised: evidence found.
1 Metasploit module
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 104 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by oracle
2022-12-1719:26Z, 31 days before disclosure
CVE published
on cve.org
2023-01-1723:35Z, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
2023-05-01, 104 days after disclosure
KEV remediation due
US federal deadline
2023-05-22, 125 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Apply updates per vendor instructions.

Affected software

Product	Affected	Fixed in
Mavencom.oracle.weblogic/weblogic-server`pkg:maven/com.oracle.weblogic/weblogic-server`Other threats	Affected =12.2.1.3.0 =12.2.1.4.0 =14.1.1.0.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

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).

Impact

For European organizations, the impact of CVE-2023-21839 is substantial due to the widespread use of Oracle WebLogic Server in sectors such as finance, telecommunications, government, and critical infrastructure. Unauthorized access to sensitive data could lead to data breaches, regulatory non-compliance (e.g., GDPR violations), intellectual property theft, and loss of customer trust. The confidentiality breach could expose personal data, trade secrets, or operational information. Given the unauthenticated nature of the exploit and network accessibility, attackers could remotely compromise systems without insider access. This increases the risk of targeted espionage or ransomware preparation. The lack of integrity or availability impact reduces the chance of service disruption but does not diminish the severity of data exposure. Organizations relying on WebLogic for critical applications must consider this vulnerability a priority to prevent potential data compromise and cascading effects on business operations.

Mitigation

1. Immediately restrict network access to T3 and IIOP ports (typically 7001, 7002, or custom ports) using firewalls or network segmentation to limit exposure to trusted hosts only. 2. Monitor network traffic for unusual or unauthorized access attempts on these protocols. 3. Apply Oracle's security advisories and patches as soon as they become available; if patches are not yet released, implement temporary workarounds recommended by Oracle or disable T3/IIOP services if feasible. 4. Conduct thorough audits of WebLogic Server configurations to ensure no unnecessary services are exposed externally. 5. Employ Web Application Firewalls (WAFs) with rules targeting WebLogic-specific attack patterns. 6. Implement strict access controls and network-level authentication where possible for management interfaces. 7. Maintain up-to-date backups and incident response plans in case of compromise. 8. Educate IT staff about this vulnerability and monitor threat intelligence feeds for emerging exploit reports.

Metasploit modules

Oracle Weblogic PreAuth Remote Command Execution via ForeignOpaqueReference IIOP Deserializationexploit · Excellent (opens in a new tab)

Nuclei detection templates

Oracle WebLogic Server - Unauthorized Accesshigh (opens in a new tab)

Public tooling indexed from Metasploit Framework, Exploit-DB and ProjectDiscovery nuclei-templates. Its existence raises the odds of exploitation; it does not confirm attacks.

CWE-306Missing Authentication for Critical Function (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #21OWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Architecture and Design
Divide the software into anonymous, normal, privileged, and administrative areas. Identify which of these areas require a proven user identity, and use a centralized authentication capability.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Architecture and Design
Where possible, avoid implementing custom, "grow-your-own" authentication routines and consider using authentication capabilities as provided by the surrounding framework, operating system, or environment.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V1.2.3 (opens in a new tab)
V1.2.2 (opens in a new tab)
V1.2.4 (opens in a new tab)
Attack patterns
Choosing Message Identifier (opens in a new tab)
Force the System to Reset Values (opens in a new tab)
Using Unpublished Interfaces or Functionality (opens in a new tab)
Cross Site Request Forgery (opens in a new tab)
Communication Channel Manipulation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2025, 22:12 UTC

Public exploits and detection1 Metasploit module, a Nuclei detection template

WeaknessesCWE-306

Technical details

References

Community reviews

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