`CVE-2020-2551` Oracle WebLogic Server

Affected software	Oracle WebLogic Server
Affected versions	10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0
Severity	9.8 Critical CVSS 3.1 3 scores
Fixed in	Oracle Critical Patch Update January 2020
Published	15 Jan 2020
Updated	13 Nov 2026

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).

Exploitation status

Exploited

Confirmed real-world exploitation.

CISA KEV listed Confirmed exploitation in the wild. Added 2023-11-16 · remediation due 2023-12-07 · ransomware use: unknown
VulnCheck KEV listed Exploitation reported in the wild. 6 citations · 11 exploits · earliest 2023-06-02.
CISA Vulnrichment exploitation: active CISA records active exploitation. Automatable: yes, technical impact: total.
Indexed PoC 9 indexed Published artifacts you can open, in GitHub PoC, Nuclei; first seen 2020-01-15.
EPSS 93% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99.8% of all scored CVEs.

VulnCheck KEV

Exploitation evidence from VulnCheck Known Exploited Vulnerabilities (VulnCheck KEV), used under VulnCheck's community terms. View CVE-2020-2551 in VulnCheck (free account), which lists 1 more citation and 6 more exploit references not shown here.

Evidence	Source	Detail	Date
Reported exploitation	blog.eclecticiq.com	/chinese-threat-actor-used-modified-cobalt-strike-variant-to-attack-taiwanese-critical-infrastructure	2023-06-02
Reported exploitation	media.kasperskycontenthub.com	/wp-content/uploads/sites/43/2023/11/09055246/Modern-Asian-APT-groups-TTPs_report_eng.pdf	2023-11-09
Reported exploitation	cisa.gov	/sites/default/files/feeds/known_exploited_vulnerabilities.json	2023-11-16
Reported exploitation	media.kasperskycontenthub.com	/wp-content/uploads/sites/43/2024/04/27161250/Kaspersky_MDR_Report_Eng_2023.pdf	2024-04-30
Reported exploitation	aquasec.com	/blog/sink-or-swim-tackling-2024s-record-breaking-vulnerability-wave	2024-09-19
Exploit reference	VulnCheck XDB 0f71a5e7f06e	Exploit type: initial-access	2020-01-19
Exploit reference	VulnCheck XDB f6dd1753be29	Exploit type: initial-access	2020-03-02
Exploit reference	VulnCheck XDB 57b91bbc3118	Exploit type: initial-access	2020-05-16
Exploit reference	VulnCheck XDB 1d921b0f29d3	Exploit type: initial-access	2020-05-24
Exploit reference	VulnCheck XDB ebf92f4c5d9b	Exploit type: initial-access	2020-06-19

Evidence

Source

Detail

Date

Reported exploitation

blog.eclecticiq.com

/chinese-threat-actor-used-modified-cobalt-strike-variant-to-attack-taiwanese-critical-infrastructure

2023-06-02

Reported exploitation

media.kasperskycontenthub.com

/wp-content/uploads/sites/43/2023/11/09055246/Modern-Asian-APT-groups-TTPs_report_eng.pdf

2023-11-09

Reported exploitation

cisa.gov

/sites/default/files/feeds/known_exploited_vulnerabilities.json

2023-11-16

Reported exploitation

media.kasperskycontenthub.com

/wp-content/uploads/sites/43/2024/04/27161250/Kaspersky_MDR_Report_Eng_2023.pdf

2024-04-30

Reported exploitation

aquasec.com

/blog/sink-or-swim-tackling-2024s-record-breaking-vulnerability-wave

2024-09-19

Exploit reference

VulnCheck XDB 0f71a5e7f06e

Exploit type: initial-access

2020-01-19

Exploit reference

VulnCheck XDB f6dd1753be29

Exploit type: initial-access

2020-03-02

Exploit reference

VulnCheck XDB 57b91bbc3118

Exploit type: initial-access

2020-05-16

Exploit reference

VulnCheck XDB 1d921b0f29d3

Exploit type: initial-access

2020-05-24

Exploit reference

VulnCheck XDB ebf92f4c5d9b

Exploit type: initial-access

2020-06-19

2 of these are GitHub repositories with fewer than 5 stars. They are listed for reference and don't count toward the exploitation status above.

Index	Artifact	Stars	First seen
GitHub PoC	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	2,080	2020-01-15
GitHub PoC	Weblogic IIOP CVE-2020-2551	336	2020-02-28
GitHub PoC	how detect CVE-2020-2551 poc exploit python Weblogic RCE with IIOP	210	2020-01-19
GitHub PoC	Weblogic Vuln POC EXP cve-2020-2551 cve-2020-2555 cve-2020-2883 ，。。。	88	2020-05-16
GitHub PoC	Weblogic RCE with IIOP	79	2020-01-18
GitHub PoC	CVE-2020-2551 POC to use in Internet	22	2020-05-24
GitHub PoC	CVE-2020-2551 Exploiter	1	2022-06-02
GitHub PoC	Use shell to build weblogic debug environment for CVE-2020-2551		2020-09-02
Nuclei	Oracle WebLogic Server - Remote Code Execution

Waratek protection

Protected by Waratek

Waratek has a rule that blocks attacks on this vulnerability.

Protection full Deserialization, Process
Action available security rule
Review human Researcher
Record active

Decided by	A researcher's recorded decision for this specific CVE
Finding	A researcher found this CVE protected by the Marshal RCE rule, ARMR Process rule.

Decided by

A researcher's recorded decision for this specific CVE

Finding

A researcher found this CVE protected by the Marshal RCE rule, ARMR Process rule.

Waratek research note

written 2026-11-13

Written by a Waratek engineer who reviewed this CVE. Their decision sets the status above, ahead of every automated rule except a withdrawal.

Comments

Rule Name: Marshal RCE rule, ARMR Process rule

How to mitigate CVE-2020-2551

Apply the fix in Oracle Critical Patch Update January 2020. Until you can, Waratek RASP blocks exploitation with its deserialization and process rules. It runs inside the Java application, with no code changes.

Waratek RASP Runtime protection for Java applications

CVSS

9.8 CRITICAL v3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 3 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H NVD Primary published

CVSS 3.0 9.8 CRITICAL CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H secalert_us@oracle.com Secondary

CVSS 2.0 7.5 none AV:N/AC:L/Au:N/C:P/I:P/A:P NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	9.8	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`	NVD	Primary	published
CVSS 3.0	9.8	CRITICAL	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`	secalert_us@oracle.com	Secondary
CVSS 2.0	7.5	none	`AV:N/AC:L/Au:N/C:P/I:P/A:P`	NVD	Primary

Affected software and releases

Oracle advisories

Advisory	Type	Quarter	Products Oracle names in its risk matrix
Oracle Critical Patch Update January 2020 ↗	CPU	2020-Q1	Oracle Fusion Middleware / WLS Core Components (10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0)

Advisory

Type

Quarter

Products Oracle names in its risk matrix

Oracle Critical Patch Update January 2020 ↗

CPU

2020-Q1

Oracle Fusion Middleware / WLS Core Components (10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0)

Oracle components and versions

Family	Component	Versions, as Oracle lists them	Read as
Oracle Fusion Middleware	WLS Core Components	10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0	10.3.6.0.0 · 12.1.3.0.0 · 12.2.1.3.0 · 12.2.1.4.0

Family

Component

Versions, as Oracle lists them

Read as

Oracle Fusion Middleware

WLS Core Components

10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0

10.3.6.0.0 · 12.1.3.0.0 · 12.2.1.3.0 · 12.2.1.4.0

Products and versions

1 product, 4 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	oracle	weblogic server	generic	10.3.6.0.0 · 12.1.3.0.0 · 12.2.1.3.0 · 12.2.1.4.0

Source

Vendor

Product

Scheme

Affected versions

nvd

oracle

weblogic server

generic

10.3.6.0.0 · 12.1.3.0.0 · 12.2.1.3.0 · 12.2.1.4.0

References

URL	Tags
https://www.oracle.com/security-alerts/cpujan2020.html
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-2551	US Government Resource

URL

Timeline

Published	2020-01-15	By the CVE Program.
VulnCheck KEV: earliest evidence	2023-06-02	Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.
Added to CISA KEV	2023-11-16	Listed in CISA's Known Exploited Vulnerabilities catalog.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.
VulnCheck KEV: latest evidence	2026-11-10	Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.
Classification created	2026-11-13	First commit adding this CVE's research note.
Last VRT activity	2026-11-13	Most recent commit touching this CVE's classification, patch or rule file.

Published

2020-01-15

By the CVE Program.

VulnCheck KEV: earliest evidence

2023-06-02

Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.

Added to CISA KEV

2023-11-16

Listed in CISA's Known Exploited Vulnerabilities catalog.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

VulnCheck KEV: latest evidence

2026-11-10

Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.

Classification created

2026-11-13

First commit adding this CVE's research note.

Last VRT activity

2026-11-13

Most recent commit touching this CVE's classification, patch or rule file.

How VRT decided (4 of 24 rules ran)

4 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification decided it matched Protected by Waratek A researcher found this CVE protected by the Marshal RCE rule, ARMR Process rule.

5 manual classification not reached Manual classification of this CVE in the legacy dataset

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

NVD ↗ · CVE.org ↗