10 minhigh
ABB Ability Zenon (CVE-2025-14847, CVE-2020-7928, CVE-2020-7921 +10 more)
CISA and ABB PSIRT published an advisory disclosing 13 MongoDB vulnerabilities affecting ABB Ability Zenon IIoT services that bundle MongoDB 4.2. The vulnerabilities span heap memory disclosure (CVE-2025-14847), denial of service via multiple vectors, IP whitelisting bypass, certificate validation failures, log injection, and local privilege escalation on Windows. No public exploitation has been reported. ABB recommends replacing the bundled MongoDB with a supported patched version or uninstalling IIoT Services if not required.
Conf:high
Showing defanged values
- cveCVE-2020-7921Improper serialization of internal state in the authorization subsystem permits a user with valid credentials to bypass IP whitelisting after administrative action.
- cveCVE-2020-7923An authorized user can cause denial of service via specially crafted queries that violate an invariant in the query subsystem's geoNear support.
- cveCVE-2020-7924A specific command line parameter intended to skip hostname checks causes MongoDB to skip all certificate validation, accepting invalid certificates.
- cveCVE-2020-7925Incorrect validation of user input in the role name parser leads to use of uninitialized memory, allowing an unauthenticated attacker to cause denial of service.
- cveCVE-2020-7928An authorized user can trigger a read overrun and access arbitrary memory via specially crafted database queries.
- cveCVE-2020-7929An authorized user can trigger denial of service by issuing specially crafted queries containing a type of regex.
- cveCVE-2021-20328The Java driver with client-side field level encryption fails to perform hostname verification on KMS server certificates, enabling MITM interception of encryption key traffic.
- cveCVE-2021-20330An attacker with basic CRUD permissions can run the applyOps command with malformed oplog entries, causing denial of service on replication secondaries.
- cveCVE-2021-20333Specially crafted commands can result in artificial or split log entries, enabling log injection or corruption.
- cveCVE-2021-20334A local attacker on a Windows machine with MongoDB Compass installed can execute arbitrary software with the privileges of the user running MongoDB Compass.
- cveCVE-2021-32036An authenticated user without specific authorizations can repeatedly invoke the features command at high volume, leading to resource depletion or lock contention.
- cveCVE-2021-32040An extremely long aggregation pipeline with a specific stage/operator can cause a stack overflow, crashing MongoDB in a DoS attack.
- cveCVE-2025-14847Mismatched length fields in Zlib compressed protocol headers allow an unauthenticated client to read uninitialized heap memory.
Detection / Hunteropenrouter
What Happened
ABB's Zenon industrial software includes a component called IIoT Services that uses an older version of MongoDB (a database program). That bundled database has 13 known security flaws. Some of these flaws could let attackers crash the system, read sensitive memory, bypass security controls, or escalate their privileges on Windows machines. Organizations in critical infrastructure sectors such as energy, water, healthcare, and manufacturing that use ABB Ability Zenon with IIoT Services are affected. The risks include operational disruption and potential data compromise. Organizations should evaluate whether they need IIoT Services, replace the bundled database with a patched version if they do, or uninstall the feature if they do not.
Key Takeaways
- ABB Ability Zenon ships with a bundled MongoDB 4.2 instance for IIoT services that is affected by 13 known MongoDB vulnerabilities ranging from Medium to High severity.
- CVE-2025-14847 allows an unauthenticated remote client to read uninitialized heap memory via mismatched length fields in Zlib compressed protocol headers.
- Multiple CVEs enable denial of service through crafted queries, regex input, aggregation pipelines, and resource depletion, impacting availability of ICS environments.
- CVE-2021-20334 permits local privilege escalation on Windows via MongoDB Compass, and CVE-2020-7921 allows bypass of IP whitelisting in MongoDB's authorization subsystem.
- ABB recommends replacing the bundled MongoDB with a supported patched version or uninstalling IIoT Services entirely if not required.
Affected Systems
- ABB Ability Zenon with IIoT services and MongoDB 4.2 installed (all versions)
- MongoDB Server 3.6 through 8.2 (various affected versions per CVE)
- MongoDB Compass 1.x on Windows (versions 1.3.0 through prior to 1.25.0)
- MongoDB Database Tools 3.6 through 100.x affected versions
- MongoDB Java driver with CSFLE support
Vulnerabilities (CVEs)
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| CVE | Product | Severity | Description |
|---|---|---|---|
| CVE-2025-14847 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | High | Mismatched length fields in Zlib compressed protocol headers allow an unauthenticated client to read uninitialized heap memory. |
| CVE-2020-7928 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | Medium | An authorized user can trigger a read overrun and access arbitrary memory via specially crafted database queries. |
| CVE-2020-7921 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | Medium | Improper serialization of internal state in the authorization subsystem permits a user with valid credentials to bypass IP whitelisting after administrative action. |
| CVE-2020-7925 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | High | Incorrect validation of user input in the role name parser leads to use of uninitialized memory, allowing an unauthenticated attacker to cause denial of service. |
| CVE-2020-7929 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | Medium | An authorized user can trigger denial of service by issuing specially crafted queries containing a type of regex. |
| CVE-2020-7923 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | Medium | An authorized user can cause denial of service via specially crafted queries that violate an invariant in the query subsystem's geoNear support. |
| CVE-2021-20330 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | Medium | An attacker with basic CRUD permissions can run the applyOps command with malformed oplog entries, causing denial of service on replication secondaries. |
| CVE-2021-32036 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | High | An authenticated user without specific authorizations can repeatedly invoke the features command at high volume, leading to resource depletion or lock contention. |
| CVE-2021-32040 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | High | An extremely long aggregation pipeline with a specific stage/operator can cause a stack overflow, crashing MongoDB in a DoS attack. |
| CVE-2021-20333 | MongoDB Server (bundled in ABB Ability Zenon IIoT services) | Medium | Specially crafted commands can result in artificial or split log entries, enabling log injection or corruption. |
| CVE-2020-7924 | MongoDB Database Tools (bundled in ABB Ability Zenon IIoT services) | Medium | A specific command line parameter intended to skip hostname checks causes MongoDB to skip all certificate validation, accepting invalid certificates. |
| CVE-2021-20328 | MongoDB Java driver with CSFLE (bundled in ABB Ability Zenon IIoT services) | Medium | The Java driver with client-side field level encryption fails to perform hostname verification on KMS server certificates, enabling MITM interception of encryption key traffic. |
| CVE-2021-20334 | MongoDB Compass on Windows (bundled in ABB Ability Zenon IIoT services) | High | A local attacker on a Windows machine with MongoDB Compass installed can execute arbitrary software with the privileges of the user running MongoDB Compass. |
Attack Chain
- Exposure: ABB Ability Zenon IIoT services run a bundled MongoDB 4.2 instance with 13 known vulnerabilities
- Initial Access: An unauthenticated or low-privileged attacker sends crafted protocol headers or database queries to the MongoDB instance
- Exploitation: Attacker triggers heap memory read (CVE-2025-14847), DoS via regex/geoNear/aggregation pipeline, or IP whitelisting bypass (CVE-2020-7921)
- Escalation: On Windows, a local attacker exploits MongoDB Compass (CVE-2021-20334) to execute code with user privileges
- Impact: System crash, data disclosure, security control bypass, or operational disruption in ICS environment
Detection Availability
- YARA Rules: No
- Sigma Rules: No
- Snort/Suricata Rules: No
- KQL Queries: No
- Splunk SPL Queries: No
- EQL Queries: No
- Other Detection Logic: No
No detection rules are provided in this advisory. The advisory is a vulnerability disclosure with mitigation guidance only.
Detection Engineering Assessment
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| Dimension | Rating | Rationale |
|---|---|---|
| EDR Visibility | Low | The vulnerabilities target a MongoDB database process. EDR may detect process crashes or unusual child process execution from MongoDB Compass (CVE-2021-20334), but database-level exploitation via crafted queries or protocol headers is unlikely to be visible to standard EDR telemetry. |
| Network Visibility | Medium | Network monitoring may detect unusual MongoDB protocol traffic patterns or large volumes of queries indicative of DoS attempts. However, legitimate MongoDB traffic may be difficult to distinguish from malicious queries without application-layer inspection. |
| Detection Difficulty | Hard | Distinguishing malicious MongoDB queries from legitimate application traffic requires deep protocol inspection and understanding of expected query patterns. The heap read vulnerability (CVE-2025-14847) is exploitable by unauthenticated clients, making it difficult to detect without network-level anomaly detection. |
Required Log Sources
- MongoDB server logs (for crash events, log injection artifacts, and unusual query patterns)
- Windows Event Logs (for local privilege escalation via MongoDB Compass)
- Network flow data (for anomalous connections to MongoDB ports)
- Process execution logs (for MongoDB Compass spawning unexpected child processes)
Hunting Hypotheses
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| Hypothesis | Telemetry | ATT&CK Stage | FP Risk |
|---|---|---|---|
| An unauthenticated client is sending malformed Zlib compressed protocol headers to a MongoDB instance to trigger heap memory disclosure via CVE-2025-14847. | Network traffic to MongoDB default port 27017 with anomalous protocol header patterns; MongoDB server crash or restart events. | Initial Access / Exploitation | Medium - legitimate clients with buggy protocol implementations could trigger similar patterns. |
| An authenticated user is issuing specially crafted regex or geoNear queries to crash MongoDB via denial of service vulnerabilities. | MongoDB query logs showing regex or geoNear queries from specific users; MongoDB process crash events following query execution. | Exploitation | Medium - legitimate application queries may use regex or geoNear functionality. |
| A local attacker on a Windows system is exploiting MongoDB Compass to execute arbitrary code with the privileges of the Compass user via CVE-2021-20334. | Process execution logs showing MongoDB Compass spawning unexpected child processes; Windows Event Logs for process creation with unusual parent-child relationships. | Execution / Privilege Escalation | Low - MongoDB Compass spawning arbitrary child processes is atypical behavior. |
| An attacker is exploiting CVE-2020-7921 to bypass MongoDB IP whitelisting after an administrative action changes authorization state. | MongoDB authentication and authorization logs showing connections from non-whitelisted IPs succeeding after admin events; network flow logs showing unexpected source IPs connecting to MongoDB. | Defense Evasion | Low - connections from non-whitelisted IPs succeeding would be anomalous by definition. |
Control Gaps
- Network-based IDS/IPS without MongoDB protocol inspection would not detect crafted query exploitation
- Standard EDR agents would not detect database-level memory disclosure or DoS via crafted queries
- Log management without MongoDB-specific log parsing would miss log injection artifacts from CVE-2021-20333
- Certificate validation bypass (CVE-2020-7924) would not be detected without TLS inspection of MongoDB tool traffic
Key Behavioral Indicators
- MongoDB process (mongod) unexpected termination or restart events
- MongoDB Compass (on Windows) spawning child processes outside its normal execution context
- Network connections to MongoDB port 27017 from unexpected source IPs, especially after administrative actions
- MongoDB log entries showing split or artificial log lines indicative of CVE-2021-20333 exploitation
- High volume of features command invocations from a single authenticated user (CVE-2021-32036)
False Positive Assessment
Low - This is a vendor-confirmed vulnerability advisory with specific affected product versions and CVE identifiers. Detection of exploitation attempts would require context-specific analysis, but the advisory itself is factual.
Recommendations
Immediate Mitigation
defender takeaway
- Verify against your organization's incident response runbook and team escalation paths before acting. Evaluate whether IIoT Services are required on ABB Ability Zenon installations; if not required, uninstall them via Control Panel to eliminate the MongoDB dependency.
- If IIoT Services are required, consider replacing the bundled MongoDB 4.2 instance with a supported and patched MongoDB version following ABB's guidance in zenHelpViewer documentation.
- If immediate replacement is not feasible, consider applying the workaround for CVE-2021-32040 by setting the mongod startup parameter internalPipelineLengthLimit=50 to reduce stack overflow risk.
Infrastructure Hardening
- Consider isolating ABB Ability Zenon systems and MongoDB instances behind firewalls, separating them from business networks as recommended by CISA ICS guidance.
- Evaluate whether remote access to these systems can be eliminated or restricted to VPN connections with proper patching.
- Consider implementing network-level access controls to limit which hosts can connect to MongoDB ports, reducing exposure of the unauthenticated heap read vulnerability (CVE-2025-14847).
- If applicable, review and enforce IP whitelisting on MongoDB instances, keeping in mind CVE-2020-7921 may allow bypass after administrative actions.
User Protection
- Consider restricting local access to Windows systems running MongoDB Compass to reduce risk of CVE-2021-20334 local privilege escalation.
- Evaluate whether MongoDB Database Tools command line parameters that skip certificate validation are in use and disable them where possible (CVE-2020-7924).
- If using the MongoDB Java driver with CSFLE, consider upgrading to a version that performs proper hostname verification on KMS server certificates (CVE-2021-20328).
Security Awareness
- Consider informing ICS operations teams about the potential for system instability or crashes due to these vulnerabilities, especially in critical manufacturing and energy environments.
- Evaluate incorporating MongoDB vulnerability awareness into existing ICS security training programs for personnel managing ABB Ability Zenon deployments.
- Consider establishing a process to monitor ABB PSIRT advisories for future updates related to this advisory (9AKK108472A9037).
MITRE ATT&CK Mapping
MITRE ATT&CK Mapping4 techniques
Tactic
Privilege Escalation
Tactic
Credential Access
Tactic
Lateral Movement
Tactic
