CVE Vulnerabilities

CVE-2023-22496

Improper Neutralization of Special Elements used in a Command ('Command Injection')

Published: Jan 14, 2023 | Modified: Jan 24, 2023
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

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.

Weakness

The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

Affected Software

Name Vendor Start Version End Version
Netdata Netdata * 1.37.0 (excluding)
Netdata Ubuntu bionic *
Netdata Ubuntu kinetic *
Netdata Ubuntu lunar *
Netdata Ubuntu trusty *
Netdata Ubuntu xenial *

Extended Description

Command injection vulnerabilities typically occur when:

Many protocols and products have their own custom command language. While OS or shell command strings are frequently discovered and targeted, developers may not realize that these other command languages might also be vulnerable to attacks. Command injection is a common problem with wrapper programs.

Potential Mitigations

  • Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

References