Description

Velociraptor allows some sensitive artifacts to be gated by additional permissions. For example, the Linux.Sys.BashShell artifact allows arbitrary command execution on endpoints, and so it requires the EXECVE permission to schedule. However, no such check was implemented for client monitoring artifacts. Additionally there was no requirement that client monitoring artifacts carry the CLIENT_EVENTS type. This allows any user who can schedule client monitoring artifacts to also schedule otherwise restricted artifacts (such as Linux.Sys.BashShell).

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.9",
  "pubDate": "2026-09-10T03:16:59.010Z",
  "pubdate": "2026-09-10T03:16:59.010Z",
  "executiveSummary": "Velociraptor contains a critical authorization bypass vulnerability related to the scheduling of client monitoring artifacts. The vulnerability originates from an inconsistent application of permission checks, specifically regarding the EXECVE permission requirement and the validation of artifact types.\nBy bypassing the intended security gating mechanisms, an authenticated user with permission to schedule client monitoring tasks can execute unauthorized, high-privilege artifacts, such as Linux.Sys.BashShell, even when they lack the required EXECVE privileges. This flaw represents a significant escalation of privilege and allows for arbitrary command execution on target endpoints.\nThe risk is severe as it enables an attacker or a compromised internal account to weaponize existing monitoring capabilities to perform unauthorized system modifications, reconnaissance, or lateral movement. Exploitation requires authenticated access to the Velociraptor server interface but does not require additional administrative privileges beyond the ability to schedule monitoring tasks. Organizations should restrict access to artifact scheduling and monitor for unauthorized execution patterns.",
  "technicalDetails": "The vulnerability resides in the core scheduling logic of Velociraptor's client monitoring engine. Certain high-sensitivity artifacts, such as Linux.Sys.BashShell, are designed to be protected by the EXECVE permission to prevent unauthorized remote command execution. The system is designed to verify these permissions before allowing the artifact to be queued for execution on a client endpoint.\nThe root cause of the vulnerability is twofold: a missing authorization check for client monitoring artifacts and a failure to enforce the CLIENT_EVENTS type requirement for these scheduled tasks. In the secure implementation, sensitive artifacts are gated by specific permission flags; however, the client monitoring subsystem failed to replicate these checks. Consequently, when a user schedules a task via the client monitoring interface, the backend service fails to validate if the artifact being requested requires elevated permissions (like EXECVE) or if the artifact matches the expected CLIENT_EVENTS criteria.\nThe attack flow follows a predictable pattern: an attacker, authenticated to the Velociraptor console with standard monitoring permissions, targets the client monitoring scheduling function. Rather than scheduling a standard monitoring artifact, the attacker submits an arbitrary artifact identifier, such as Linux.Sys.BashShell. Because the backend validation logic ignores the permission gating for client monitoring tasks, the scheduler accepts the request. The request is then serialized and distributed to the target endpoint agent. Upon receiving the malicious task, the endpoint agent—relying on the server's validation—executes the command as if it were a legitimate authorized monitoring request.\nThis bypass allows for a complete compromise of the endpoint host. Because Velociraptor agents operate with high system privileges (often root or SYSTEM), the execution of arbitrary commands via Linux.Sys.BashShell grants the attacker total control over the underlying operating system. This is a post-authentication privilege escalation that negates the granular permission model Velociraptor provides, effectively granting an attacker the capabilities of an administrator. The vulnerability remains present in configurations where users are granted 'monitor' access without sufficient oversight of the artifacts they are permitted to schedule, demonstrating a failure to maintain consistent security invariants across the application's task distribution framework."
}