Netdata is an open source option for real-time infrastructure monitoring and troubleshooting. An attacker with the ability to establish a streaming connection can execute arbitrary commands on the targeted Netdata agent. When an alert is triggered, the function health_alarm_execute is called. This function performs different checks and then enqueues a command by calling spawn_enq_cmd. This command is populated with several arguments that are not sanitized. One of them is the registry_hostname of the node for which the alert is raised. By providing a specially crafted registry_hostname as part of the health data that is streamed to a Netdata (parent) agent, an attacker can execute arbitrary commands at the remote host as a side-effect of the raised alert. Note that the commands are executed as the user running the Netdata Agent. This user is usually named netdata. The ability to run arbitrary commands may allow an attacker to escalate privileges by escalating other vulnerabilities in the system, as that user. The problem has been fixed in: Netdata agent v1.37 (stable) and Netdata agent v1.36.0-409 (nightly). As a workaround, streaming is not enabled by default. If you have previously enabled this, it can be disabled. Limiting access to the port on the recipient Agent to trusted child connections may mitigate the impact of this vulnerability.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Netdata | Netdata | * | 1.37.0 (excluding) |
| Netdata | Ubuntu | bionic | * |
| Netdata | Ubuntu | kinetic | * |
| Netdata | Ubuntu | lunar | * |
| Netdata | Ubuntu | mantic | * |
| Netdata | Ubuntu | trusty | * |
| Netdata | Ubuntu | xenial | * |
Input validation is a frequently-used technique for checking potentially dangerous inputs in order to ensure that the inputs are safe for processing within the code, or when communicating with other components. When software does not validate input properly, an attacker is able to craft the input in a form that is not expected by the rest of the application. This will lead to parts of the system receiving unintended input, which may result in altered control flow, arbitrary control of a resource, or arbitrary code execution. Input validation is not the only technique for processing input, however. Other techniques attempt to transform potentially-dangerous input into something safe, such as filtering (CWE-790) - which attempts to remove dangerous inputs - or encoding/escaping (CWE-116), which attempts to ensure that the input is not misinterpreted when it is included in output to another component. Other techniques exist as well (see CWE-138 for more examples.) Input validation can be applied to:
Data can be simple or structured. Structured data can be composed of many nested layers, composed of combinations of metadata and raw data, with other simple or structured data. Many properties of raw data or metadata may need to be validated upon entry into the code, such as:
Implied or derived properties of data must often be calculated or inferred by the code itself. Errors in deriving properties may be considered a contributing factor to improper input validation.
Note that “input validation” has very different meanings to different people, or within different classification schemes. Caution must be used when referencing this CWE entry or mapping to it. For example, some weaknesses might involve inadvertently giving control to an attacker over an input when they should not be able to provide an input at all, but sometimes this is referred to as input validation. Finally, it is important to emphasize that the distinctions between input validation and output escaping are often blurred, and developers must be careful to understand the difference, including how input validation is not always sufficient to prevent vulnerabilities, especially when less stringent data types must be supported, such as free-form text. Consider a SQL injection scenario in which a person’s last name is inserted into a query. The name “O’Reilly” would likely pass the validation step since it is a common last name in the English language. However, this valid name cannot be directly inserted into the database because it contains the “’” apostrophe character, which would need to be escaped or otherwise transformed. In this case, removing the apostrophe might reduce the risk of SQL injection, but it would produce incorrect behavior because the wrong name would be recorded.