CVE-2021-2054
📋 TL;DR
This vulnerability in Oracle Database Server's RDBMS Sharding component allows high-privileged attackers with specific database privileges (Create Any Procedure, Create Any View, Create Any Trigger) and network access via Oracle Net to compromise the sharding system. Successful exploitation can lead to complete takeover of RDBMS Sharding, affecting Oracle Database versions 12.2.0.1, 18c, and 19c.
💻 Affected Systems
- Oracle Database Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of RDBMS Sharding allowing attacker to execute arbitrary code, access/modify all sharded data, and disrupt database availability.
Likely Case
Privileged database user exploits the vulnerability to gain unauthorized access to sharded data and potentially escalate privileges within the database environment.
If Mitigated
Limited impact due to proper privilege separation, network segmentation, and access controls preventing high-privileged attackers from reaching vulnerable components.
🎯 Exploit Status
Vulnerability is described as 'easily exploitable' but requires specific high-level database privileges. No public exploit code identified in references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply patches from Oracle Critical Patch Update January 2021
Vendor Advisory: https://www.oracle.com/security-alerts/cpujan2021.html
Restart Required: Yes
Instructions:
1. Download appropriate patch from Oracle Support. 2. Apply patch following Oracle's patching procedures. 3. Restart database instances. 4. Verify patch application.
🔧 Temporary Workarounds
Restrict Privileges
allRemove or restrict Create Any Procedure, Create Any View, Create Any Trigger privileges from users who don't absolutely need them.
REVOKE CREATE ANY PROCEDURE FROM <username>;
REVOKE CREATE ANY VIEW FROM <username>;
REVOKE CREATE ANY TRIGGER FROM <username>;
Network Access Control
allRestrict Oracle Net access to only trusted hosts and networks using firewall rules and Oracle Net configuration.
# Configure Oracle Net listener.ora to restrict access
# Use firewall rules to limit connections to database ports
🧯 If You Can't Patch
- Implement strict principle of least privilege for database users, especially for Create Any privileges
- Segment database network and implement strict access controls to limit Oracle Net exposure
🔍 How to Verify
Check if Vulnerable:
Check Oracle Database version and if RDBMS Sharding component is installed: SELECT * FROM v$version; and check for sharding components.Check Version:
SELECT * FROM v$version;Verify Fix Applied:
Verify patch application through Oracle OPatch utility: opatch lsinventory | grep -i 'Critical Patch Update'📡 Detection & Monitoring
Log Indicators:
- Unusual CREATE PROCEDURE/VIEW/TRIGGER statements from unexpected users
- Failed privilege escalation attempts in audit logs
- Unusual network connections to Oracle Net ports
Network Indicators:
- Unexpected Oracle Net connections from unauthorized sources
- Suspicious database protocol traffic patterns
SIEM Query:
source="oracle_audit" AND (event_type="CREATE" AND (object_type="PROCEDURE" OR object_type="VIEW" OR object_type="TRIGGER")) AND user NOT IN ("authorized_users")