CVE-2021-2204 Overview
CVE-2021-2204 is an information disclosure vulnerability affecting the Core component of Oracle WebLogic Server, a widely deployed Java EE application server within Oracle Fusion Middleware. This easily exploitable vulnerability allows an unauthenticated attacker with network access via HTTP to compromise Oracle WebLogic Server, resulting in unauthorized read access to a subset of server-accessible data.
Critical Impact
Unauthenticated attackers can remotely access sensitive data on affected Oracle WebLogic Server instances without any user interaction or special privileges required.
Affected Products
- Oracle WebLogic Server 10.3.6.0.0
- Oracle WebLogic Server 12.1.3.0.0
- Oracle WebLogic Server 12.2.1.3.0
- Oracle WebLogic Server 12.2.1.4.0
- Oracle WebLogic Server 14.1.1.0.0
Discovery Timeline
- April 22, 2021 - CVE-2021-2204 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2021-2204
Vulnerability Analysis
This vulnerability resides in the Core component of Oracle WebLogic Server, which handles fundamental server operations and request processing. The flaw allows unauthenticated attackers to gain unauthorized read access to sensitive data through network-based attacks over HTTP. The vulnerability requires no user interaction and can be exploited remotely, making it particularly concerning for internet-facing WebLogic deployments.
The attack complexity is low, meaning that exploitation does not require specialized conditions or extensive technical knowledge. Since the vulnerability affects the Core component, it impacts fundamental server functionality rather than an optional feature, increasing the breadth of affected deployments.
Root Cause
The root cause of CVE-2021-2204 stems from improper access control mechanisms within the Oracle WebLogic Server Core component. The vulnerability allows unauthorized read operations on server-accessible data due to insufficient validation of incoming HTTP requests. This information disclosure weakness enables attackers to extract sensitive configuration data, application information, or other accessible server resources without authentication.
Attack Vector
The attack vector for this vulnerability is network-based, specifically targeting HTTP endpoints exposed by Oracle WebLogic Server. An attacker can exploit this vulnerability by:
- Identifying an exposed Oracle WebLogic Server instance running a vulnerable version
- Crafting HTTP requests targeting the Core component
- Bypassing authentication requirements to access protected data
- Extracting sensitive information from the server response
The vulnerability requires no authentication (PR:N), no user interaction (UI:N), and can be exploited over the network (AV:N) with low attack complexity (AC:L). The impact is limited to confidentiality (C:L) with no integrity or availability impact.
Detection Methods for CVE-2021-2204
Indicators of Compromise
- Unusual HTTP requests to WebLogic Server endpoints from untrusted IP addresses
- Anomalous data access patterns or unexpected read operations on server resources
- Increased HTTP traffic to administrative or core WebLogic components
- Log entries showing unauthenticated access attempts to protected resources
Detection Strategies
- Monitor WebLogic Server access logs for suspicious HTTP request patterns targeting Core component endpoints
- Implement network intrusion detection rules to identify exploitation attempts against known WebLogic vulnerabilities
- Deploy web application firewalls (WAF) with rules to detect and block anomalous requests to WebLogic Server
- Use SIEM solutions to correlate access logs and identify potential data exfiltration attempts
Monitoring Recommendations
- Enable verbose logging on Oracle WebLogic Server to capture detailed request information
- Configure alerts for unauthenticated access attempts to sensitive server resources
- Implement network traffic analysis to detect unusual data flows from WebLogic Server instances
- Regularly review server access logs for patterns consistent with information disclosure attacks
How to Mitigate CVE-2021-2204
Immediate Actions Required
- Apply the Oracle Critical Patch Update (CPU) from April 2021 to all affected WebLogic Server instances
- Restrict network access to WebLogic Server administrative interfaces using firewall rules
- Implement network segmentation to limit exposure of WebLogic Server to untrusted networks
- Review and audit current WebLogic Server configurations for unnecessary exposed endpoints
Patch Information
Oracle has released security patches addressing CVE-2021-2204 in the April 2021 Critical Patch Update. Organizations running affected versions (10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0, and 14.1.1.0.0) should prioritize applying this patch. The patch should be obtained directly from Oracle Support and tested in a non-production environment before deployment to production systems.
Workarounds
- Restrict network access to Oracle WebLogic Server instances to trusted IP ranges only
- Place WebLogic Server behind a reverse proxy or WAF that can filter malicious requests
- Disable or restrict access to unnecessary WebLogic Server endpoints and services
- Implement strong network segmentation to isolate WebLogic Server from public-facing networks
# Example: Restrict WebLogic Server access using iptables
# Allow access only from trusted internal network
iptables -A INPUT -p tcp --dport 7001 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 7001 -j DROP
# Verify WebLogic Server version for patch applicability
java -cp $WL_HOME/server/lib/weblogic.jar weblogic.version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
