CVE-2025-36010 Overview
CVE-2025-36010 is a denial of service vulnerability affecting IBM Db2 for Linux versions 12.1.0, 12.1.1, and 12.1.2. The vulnerability allows an unauthenticated remote attacker to cause a denial of service condition due to a deadlock scenario where executable segments wait for each other to release necessary locks.
Critical Impact
Unauthenticated attackers can remotely disrupt database availability by triggering a deadlock condition, potentially impacting business-critical applications and services relying on IBM Db2.
Affected Products
- IBM Db2 for Linux 12.1.0
- IBM Db2 for Linux 12.1.1
- IBM Db2 for Linux 12.1.2
Discovery Timeline
- 2025-07-29 - CVE-2025-36010 published to NVD
- 2025-08-06 - Last updated in NVD database
Technical Details for CVE-2025-36010
Vulnerability Analysis
This vulnerability is classified under CWE-833 (Deadlock), a race condition type flaw where concurrent operations create a circular dependency on shared resources. In the context of IBM Db2, executable segments within the database engine enter a state where each segment holds a lock that another segment requires, creating an unresolvable circular wait condition.
The network-accessible nature of this vulnerability is particularly concerning for enterprise environments where Db2 databases often serve as backend systems for critical business applications. An unauthenticated attacker can exploit this flaw remotely without requiring any user interaction, making it an attractive target for disrupting database operations.
The impact is limited to availability—there is no confidentiality or integrity breach associated with this vulnerability. However, in environments where database uptime is critical, such as financial services, healthcare, or e-commerce platforms, even temporary denial of service can result in significant operational and financial consequences.
Root Cause
The root cause of CVE-2025-36010 lies in improper lock management within IBM Db2's execution engine. When multiple executable segments compete for shared resources, the locking mechanism fails to prevent circular dependencies. This results in a deadlock state where:
- Segment A holds Lock 1 and waits for Lock 2
- Segment B holds Lock 2 and waits for Lock 1
Neither segment can proceed, causing the database to hang or become unresponsive. This is a classic deadlock scenario that indicates insufficient lock ordering or deadlock detection and recovery mechanisms in the affected versions.
Attack Vector
The attack can be initiated remotely over the network by an unauthenticated user. The attacker needs to craft requests that trigger the specific sequence of lock acquisitions leading to the deadlock condition. Since no authentication is required, the attack surface is significant for any Db2 instance exposed to untrusted networks.
The exploitation does not require sophisticated techniques—the attacker simply needs to generate database operations that cause multiple executable segments to compete for locks in a pattern that produces the circular wait condition. This could potentially be achieved through specially crafted database queries or connection patterns.
Detection Methods for CVE-2025-36010
Indicators of Compromise
- Database queries experiencing unexpected timeouts or hanging indefinitely
- IBM Db2 process consuming resources but not completing operations
- Multiple concurrent connections in waiting state with no progress
- Database administrative commands becoming unresponsive
Detection Strategies
- Monitor Db2 lock wait events using db2pd -locks command for circular dependencies
- Implement database health checks that alert on abnormal lock acquisition patterns
- Configure Db2 diagnostic logging to capture deadlock events and lock escalations
- Deploy network monitoring to detect unusual connection patterns to Db2 ports
Monitoring Recommendations
- Enable Db2 lock monitoring with LOCKTIMEOUT parameter to detect prolonged waits
- Set up automated alerts for database unresponsiveness lasting beyond defined thresholds
- Monitor system resources (CPU, memory) for patterns indicative of deadlock conditions
- Review Db2 diagnostic logs (db2diag.log) regularly for deadlock-related messages
How to Mitigate CVE-2025-36010
Immediate Actions Required
- Review IBM's security advisory and apply the recommended patches immediately
- Restrict network access to Db2 instances using firewalls and network segmentation
- Implement connection rate limiting to reduce potential for exploitation
- Enable monitoring for deadlock conditions and configure automated restart procedures
Patch Information
IBM has released a security update addressing this vulnerability. Administrators should consult the IBM Support Page for detailed patch information and upgrade instructions. The advisory provides specific guidance on updating IBM Db2 for Linux installations to remediated versions.
Workarounds
- Implement network-level access controls to limit connections to trusted sources only
- Configure LOCKTIMEOUT database parameter to automatically abort long-running lock waits
- Deploy load balancers with health checks to detect and route around unresponsive instances
- Consider implementing connection pooling with timeout configurations to limit exposure
# Example: Configure lock timeout to mitigate prolonged deadlocks
db2 "UPDATE DB CFG FOR <database_name> USING LOCKTIMEOUT 60"
# Restrict network access to Db2 port (default 50000) using iptables
iptables -A INPUT -p tcp --dport 50000 -s <trusted_network>/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 50000 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
