Horizon Alert
Summary of the vulnerability and why it matters
A critical vulnerability has been identified in Moquette, a Java-based MQTT broker, which could allow unauthorized access to data across different tenants. This issue stems from how the broker handles specially crafted client identifiers or usernames when configured with pattern-based access rules, potentially leading to a compromise of data confidentiality and integrity. The main concern is confirming relevance and exposure within your environment.
- Broker vulnerability allows cross-tenant data access.
- Critical flaw impacts secure messaging infrastructure.
- Confirm relevance and assess your exposure.
Attack Path
How an attacker could exploit the issue
An attacker could gain unauthorized access to sensitive data and potentially disrupt service by exploiting a vulnerability in Moquette's authorization system. This occurs when pattern-based access control rules are used, and an attacker can manipulate their client ID or username to include special characters. These characters are then processed incorrectly, allowing the attacker to bypass intended restrictions and interact with topics they shouldn't, or even cause the broker to crash.
- Requires authenticated access.
- Triggers vulnerability with crafted client identity.
- Leads to data access and service disruption.
Live Threat
Current exploitation, exposure, and threat context
When pattern-based access control rules are configured, an attacker could exploit this vulnerability by using special characters in their client ID or username. This could allow them to gain unauthorized read and write access to data across different tenants, or to disrupt service by causing a NullPointerException.
- Cross-tenant data read/write access.
- Impersonation via client ID/username manipulation.
- Service disruption via unexpected errors.
Operational Fix
Recommended remediation, mitigation, and detection steps
Teams responsible for Moquette, a Java MQTT broker, should focus on identifying instances and assessing their criticality. The initial steps involve locating all deployments of Moquette, determining their network reachability, and confirming their business importance. Subsequently, the accountable owner must be identified to plan remediation efforts based on the assessed risk.
- App/Platform teams likely own Moquette.
- Verify Moquette deployment reachability and criticality.
- Plan remediation based on risk and ownership.
