CVE-2025-61019 Overview
CVE-2025-61019 affects the sqlo_key_part_best component in OpenLink Virtuoso open-source edition version 7.2.11. Attackers can trigger a Denial of Service (DoS) condition by submitting crafted SQL statements to a vulnerable Virtuoso instance. The flaw resides in the SQL query optimizer, which handles key-part selection during query planning. Successful exploitation disrupts database availability for legitimate users and applications relying on the Virtuoso server.
Critical Impact
A crafted SQL statement sent to Virtuoso 7.2.11 can crash or hang the database engine, interrupting service for connected applications and dependent workloads.
Affected Products
- OpenLink Virtuoso Open Source Edition v7.2.11
- Deployments exposing SQL endpoints to untrusted users
- Applications embedding the Virtuoso 7.2.11 query engine
Discovery Timeline
- 2026-06-23 - CVE-2025-61019 published to the National Vulnerability Database (NVD)
- 2026-06-23 - Last updated in NVD database
Technical Details for CVE-2025-61019
Vulnerability Analysis
The issue resides in the sqlo_key_part_best routine, part of Virtuoso's SQL optimizer responsible for selecting the best index key part during query planning. A crafted SQL statement steers the optimizer into a state that produces a Denial of Service condition, terminating or stalling the database process. The affected build is virtuoso-opensource v7.2.11. The vulnerability is tracked publicly through the GitHub Issue Discussion. The current EPSS probability is 0.149%, indicating low observed exploitation likelihood at this time.
Root Cause
The root cause sits in the optimizer's handling of specific query shapes evaluated by sqlo_key_part_best. Improper handling of attacker-controlled input during cost or key-part evaluation triggers an unrecoverable condition. Refer to the upstream issue for reproducer details and technical analysis.
Attack Vector
An attacker submits a crafted SQL statement to the Virtuoso SQL interface. Any account able to execute arbitrary SQL against the server can reach the vulnerable code path. Exposure increases sharply when SQL endpoints, SPARQL-to-SQL bridges, or web applications forward untrusted input to the database. No verified exploit code is publicly available; see the GitHub Issue Discussion for the reported reproducer.
Detection Methods for CVE-2025-61019
Indicators of Compromise
- Repeated Virtuoso process crashes or unexpected restarts of the virtuoso-t daemon.
- Sudden spikes in CPU or memory consumption tied to SQL query execution.
- Client errors reporting lost database connections shortly after specific queries.
Detection Strategies
- Inspect Virtuoso server logs for abnormal termination entries and recurring fatal errors during query planning.
- Capture and review SQL statements that precede service interruptions to identify malformed or unusual constructs.
- Correlate database availability alerts with authenticated session activity to identify abusive clients.
Monitoring Recommendations
- Track virtuoso-t uptime, crash counts, and restart frequency through host monitoring.
- Alert on sustained query latency increases or connection-pool exhaustion against Virtuoso endpoints.
- Log all SQL submitted from external-facing applications for post-incident review.
How to Mitigate CVE-2025-61019
Immediate Actions Required
- Restrict network access to Virtuoso SQL ports so only trusted clients can submit queries.
- Require authentication for all SQL endpoints and revoke ad-hoc query rights from low-trust accounts.
- Place a query proxy or application layer between untrusted users and the database to filter crafted statements.
Patch Information
No fixed version is documented in the available CVE data. Monitor the GitHub Issue Discussion and the OpenLink Virtuoso repository for an official fix, then upgrade beyond v7.2.11 once a patched release is published.
Workarounds
- Limit SQL execution privileges to vetted application accounts and disable interactive SQL for end users.
- Deploy rate limiting and query timeouts to reduce the impact of malformed statements reaching the optimizer.
- Run Virtuoso under a process supervisor that restarts the service after a crash to shorten downtime windows.
# Configuration example: restrict Virtuoso SQL port to localhost in virtuoso.ini
[Parameters]
ServerPort = 1111
ServerThreads = 20
CheckpointInterval = 60
MaxClientConnections = 50
# Bind only to loopback to block remote SQL submission
ListenIPv4 = 127.0.0.1
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
