`CVE-2020-2883` 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 April 2020
Published	15 Apr 2020
Updated	13 Nov 2026

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).

Exploitation status

Exploited

Confirmed real-world exploitation.

CISA KEV listed Confirmed exploitation in the wild. Added 2025-01-07 · remediation due 2025-01-28 · ransomware use: unknown
VulnCheck KEV listed Exploitation reported in the wild. 5 citations · 10 exploits · earliest 2020-04-30.
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, Metasploit, Nuclei; first seen 2020-05-10.
EPSS 95% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99.9% of all scored CVEs.

VulnCheck KEV

Exploitation evidence from VulnCheck Known Exploited Vulnerabilities (VulnCheck KEV), used under VulnCheck's community terms. View CVE-2020-2883 in VulnCheck (free account), which lists 5 more exploit references not shown here.

Evidence	Source	Detail	Date
Reported exploitation	blogs.oracle.com	/security/post/customers-should-apply-the-april-2020-critical-patch-update-without-delay	2020-04-30
Reported exploitation	cisa.gov	/news-events/alerts/2020/05/01/unpatched-oracle-weblogic-servers-vulnerable-cve-2020-2883	2020-05-01
Reported exploitation	cisa.gov	/sites/default/files/feeds/known_exploited_vulnerabilities.json	2025-01-07
Reported exploitation	cyble.com	/resources/research-reports/global-cybersecurity-report	2025-12-11
Reported exploitation	loginsoft.com	/reports/annually/vulnerability-intelligence-report-2025	2026-01-20
Exploit reference	VulnCheck XDB da341a09bc60	Exploit type: initial-access	2020-04-01
Exploit reference	VulnCheck XDB 7927833b7021	Exploit type: initial-access	2020-05-10
Exploit reference	VulnCheck XDB d55ddb5fac32	Exploit type: initial-access	2020-05-16
Exploit reference	VulnCheck XDB 9ab580b3f80b	Exploit type: initial-access	2020-06-30
Exploit reference	VulnCheck XDB da7b6fb2895f	Exploit type: initial-access	2020-08-19

Evidence

Source

Detail

Date

Reported exploitation

blogs.oracle.com

/security/post/customers-should-apply-the-april-2020-critical-patch-update-without-delay

2020-04-30

Reported exploitation

cisa.gov

/news-events/alerts/2020/05/01/unpatched-oracle-weblogic-servers-vulnerable-cve-2020-2883

2020-05-01

Reported exploitation

cisa.gov

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

2025-01-07

Reported exploitation

cyble.com

/resources/research-reports/global-cybersecurity-report

2025-12-11

Reported exploitation

loginsoft.com

/reports/annually/vulnerability-intelligence-report-2025

2026-01-20

Exploit reference

VulnCheck XDB da341a09bc60

Exploit type: initial-access

2020-04-01

Exploit reference

VulnCheck XDB 7927833b7021

Exploit type: initial-access

2020-05-10

Exploit reference

VulnCheck XDB d55ddb5fac32

Exploit type: initial-access

2020-05-16

Exploit reference

VulnCheck XDB 9ab580b3f80b

Exploit type: initial-access

2020-06-30

Exploit reference

VulnCheck XDB da7b6fb2895f

Exploit type: initial-access

2020-08-19

3 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利用CVE-2020-2883打Shiro rememberMe反序列化漏洞，一键注册蚁剑filter内存shell	529	2020-08-19
GitHub PoC	Weblogic coherence.jar RCE	175	2020-05-10
GitHub PoC	Proof of concept for Weblogic CVE-2020-2883	15	2020-05-13
GitHub PoC	CVE-2020-2883	5	2020-11-26
GitHub PoC	FancyDoesSecurity/CVE-2020-2883	2	2020-10-14
GitHub PoC	POC for CVE-2020-2883		2021-11-15
GitHub PoC	适配12.2.1.3和12.2.1.4版本		2020-06-09
Nuclei	Oracle WebLogic Server - Remote Code Execution
Metasploit	WebLogic Server Deserialization RCE BadAttributeValueExpException ExtComp (normal rank)

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-2020-2883

Apply the fix in Oracle Critical Patch Update April 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 April 2020 ↗	CPU	2020-Q2	Oracle Fusion Middleware / Core (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 April 2020 ↗

CPU

2020-Q2

Oracle Fusion Middleware / Core (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	Core	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

Core

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/cpuapr2020.html
http://packetstormsecurity.com/files/157950/WebLogic-Server-Deserialization-Remote-Code-Execution.html	Third Party Advisory, VDB Entry
https://www.zerodayinitiative.com/advisories/ZDI-20-504/	Third Party Advisory, VDB Entry
https://www.zerodayinitiative.com/advisories/ZDI-20-570/	Third Party Advisory, VDB Entry
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-2883	US Government Resource

URL

Timeline

Published	2020-04-15	By the CVE Program.
VulnCheck KEV: earliest evidence	2020-04-30	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	2025-01-07	Listed in CISA's Known Exploited Vulnerabilities catalog.
VulnCheck KEV: latest evidence	2026-01-20	Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.
NVD record modified	2026-06-17	NVD's own last-modified date for this 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

2020-04-15

By the CVE Program.

VulnCheck KEV: earliest evidence

2020-04-30

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

2025-01-07

Listed in CISA's Known Exploited Vulnerabilities catalog.

VulnCheck KEV: latest evidence

2026-01-20

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

NVD record modified

2026-06-17

NVD's own last-modified date for this 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 ↗