Exploited vulnerability · CISA KEV

Is CVE-2023-21839 exploited? Yes: in CISA KEV since 1 May 2023

Gociux · Oracle WebLogic Server · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2023-21839, Oracle WebLogic Server Unspecified Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 1 May 2023, 104 days after it was published. It affects Oracle WebLogic Server. If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 1 May 2023

ransomwareNot knownno confirmed use

EPSStop 1%among the most likely CVEs to be exploited

severity7.5CVSS 3.1 · high

US federal due22 May 2023BOD 22-01 deadline

What it is

Oracle WebLogic Server contains an unspecified vulnerability that allows an unauthenticated attacker with network access via T3, IIOP, to compromise Oracle WebLogic Server.

Vendor	Oracle (46 exploited CVEs in KEV)
Product	WebLogic Server
Vulnerability	Oracle WebLogic Server Unspecified Vulnerability
Weakness	not specified
Published	17 Jan 2023
Added to KEV	1 May 2023
Reported by (CNA)	oracle

What to do

Check whether you run it. Look for WebLogic Server in your asset inventory, including appliances and cloud images. Stack check lists every exploited Oracle CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 17 Jan 2023.
Get told next time. Email alerts when CISA adds a CVE for Oracle.

Other exploited CVEs in WebLogic Server

CVE-2024-21182: Oracle WebLogic Server Unspecified Vulnerability (1 Jun 2026)
CVE-2020-2883: Oracle WebLogic Server Unspecified Vulnerability (7 Jan 2025)
CVE-2020-14644: Oracle WebLogic Server Remote Code Execution Vulnerability (18 Sep 2024)
CVE-2017-3506: Oracle WebLogic Server OS Command Injection Vulnerability (3 Jun 2024)
CVE-2018-2628: Oracle WebLogic Server Unspecified Vulnerability (8 Sep 2022)
CVE-2017-10271: Oracle Corporation WebLogic Server Remote Code Execution Vulnerability (10 Feb 2022)

References

Questions

Is CVE-2023-21839 being exploited?

Yes. CISA added CVE-2023-21839 to the Known Exploited Vulnerabilities catalog on 1 May 2023, which means there is reliable evidence of exploitation in the wild.

Is CVE-2023-21839 used in ransomware attacks?

CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.

How do I fix CVE-2023-21839?

Apply updates per vendor instructions. Check Oracle's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected WebLogic Server and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2023 · Oracle scorecard · act-now radar.

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