CVE-2021-35592

What it actually does

CVE-2021-35592 is an improper input validation vulnerability in Oracle MySQL Cluster, specifically the Cluster: General component. An attacker who already has high privileges and access to the adjacent physical communication segment used by the MySQL Cluster can, with required user interaction, cause the cluster to process malicious or malformed input in a way that can compromise confidentiality, integrity, and availability. Successful exploitation can result in full takeover of the MySQL Cluster, meaning the attacker may be able to control cluster behavior, access or alter data, and disrupt clustered database services.

Why it matters to the business

A successful attack could lead to loss of control over clustered MySQL database infrastructure, exposing sensitive data, enabling unauthorized data modification, and causing service outages for applications that rely on MySQL Cluster. The exploit conditions are restrictive—adjacent network/physical segment access, high privileges, high attack complexity, and user interaction are required—but the potential impact is severe because compromise can result in takeover of the database cluster. The EPSS score is elevated despite no known CISA KEV listing, so organizations running affected Oracle MySQL Cluster versions or downstream products such as NetApp OnCommand Insight or NetApp SnapCenter should treat remediation as important, especially in environments where cluster management networks are shared or insufficiently segmented.

How an attack unfolds

An attacker first obtains high-privileged access in or near the environment where MySQL Cluster operates and positions themselves on the physical or adjacent communication segment used by the cluster nodes. They then identify affected MySQL Cluster versions—7.5.23 or earlier, 7.6.19 or earlier, or 8.0.26 or earlier—and craft input that abuses insufficient validation in the Cluster: General component. Because exploitation requires user interaction, the attacker must induce an authorized person or process to perform an action that causes the vulnerable cluster component to process the malicious input. If successful, the malformed input leads to compromise of the MySQL Cluster, potentially allowing the attacker to take over cluster operations, manipulate data, access sensitive records, or disrupt availability.

How to fix it

Upgrade Oracle MySQL Cluster to a vendor-fixed release newer than the affected branches: later than 7.5.23 for the 7.5 line, later than 7.6.19 for the 7.6 line, and later than 8.0.26 for the 8.0 line. If using downstream or bundled products such as NetApp OnCommand Insight or NetApp SnapCenter, apply the corresponding vendor updates or advisories that include the fixed MySQL Cluster components. Where immediate patching is not possible, restrict access to MySQL Cluster communication and management segments, enforce strong network segmentation, limit administrative privileges, disable unnecessary cluster interfaces, monitor administrative workflows requiring user interaction, and ensure only trusted operators can initiate cluster management actions. Review Oracle CPU advisories and product-specific vendor guidance for exact supported upgrade paths before applying changes in production.

How to confirm the fix worked

Confirm that all MySQL Cluster nodes report versions newer than the affected releases: 7.5.23, 7.6.19, or 8.0.26 depending on the deployed branch. Verify that NetApp OnCommand Insight, NetApp SnapCenter, or other bundled products have been updated to vendor releases that address this vulnerability. Validate that cluster communication ports and management interfaces are reachable only from authorized systems on segmented networks. Review configuration and firewall rules to ensure no untrusted adjacent access exists to the physical communication segment. Conduct a controlled post-upgrade functional test of cluster node communication, failover, replication, and management operations to confirm the cluster remains healthy after remediation.

Typical attack path

1. Gain high-privileged access to systems or management paths associated with the MySQL Cluster environment.
2. Obtain access to the physical or adjacent communication segment used by MySQL Cluster nodes.
3. Enumerate MySQL Cluster versions and identify deployments running affected releases: 7.5.23 and prior, 7.6.19 and prior, or 8.0.26 and prior.
4. Prepare malicious or malformed input targeting improper validation in the Cluster: General component.
5. Trigger required user interaction by inducing an administrator, operator, or legitimate workflow to process the attacker-controlled input.
6. Exploit the vulnerable cluster component to compromise MySQL Cluster.
7. Use cluster takeover to access data, alter database contents, change cluster behavior, or disrupt service availability.

How to detect it

Look for evidence of suspicious privileged activity and abnormal MySQL Cluster behavior around the time of potential exposure. Relevant log sources include MySQL Cluster management server logs, data node logs, SQL/API node logs, operating system authentication logs, sudo/admin command logs, network access logs for cluster communication segments, firewall logs, and logs from products bundling MySQL Cluster such as NetApp OnCommand Insight or NetApp SnapCenter. Investigate unexpected cluster node restarts, node failures, management server disconnects, node membership changes, configuration changes, unexplained failovers, malformed packet or protocol errors, and administrative actions performed shortly before cluster instability. Correlate these events with privileged logins from unusual hosts, access from systems not normally present on the cluster communication segment, and operator actions that may have processed untrusted input. No unique public exploit string is available, so detection should focus on behavioral indicators of cluster manipulation, anomalous adjacent-network access, and unauthorized administrative activity.

• ndb_mgmd
• ndbd
• ndbmtd
• mysqld
• Node failure
• Node restart
• Node shutdown
• Node disconnected
• Cluster configuration changed
• Arbitration failure
• Transporter connection failed
• Invalid signal
• Invalid configuration
• Malformed
• Protocol error
• Unexpected node failure
• Management server disconnected
• Data node disconnected

What your security team should do

• Inventory all Oracle MySQL Cluster deployments and downstream products that may bundle or depend on MySQL Cluster, including NetApp OnCommand Insight and NetApp SnapCenter.
• Prioritize patching clusters running MySQL Cluster 7.5.23 or earlier, 7.6.19 or earlier, or 8.0.26 or earlier, especially where cluster networks are shared or accessible beyond a tightly controlled management plane.
• Restrict and monitor access to MySQL Cluster communication segments, management interfaces, and administrative workflows while patching is scheduled.
• Review privileged accounts with access to MySQL Cluster hosts and management paths; remove unnecessary privileges and enforce multi-factor authentication where applicable.
• Search logs for unusual cluster administration activity, unexpected node membership changes, configuration changes, crashes, restarts, or errors involving malformed cluster messages.
• Ensure downstream vendor appliances or applications using MySQL Cluster receive vendor-supported updates rather than only patching standalone database packages.
• Because the EPSS score is elevated, maintain heightened monitoring even though the vulnerability is not listed in CISA KEV and no public exploit maturity is reported.