Description

A security flaw has been discovered in rcourtman Pulse up to 6.0.4/6.1.0-rc.4. Affected by this issue is the function fmt.Sprintf of the file /api/security/quick-setup of the component Quick Security Setup Handler. The manipulation of the argument Username results in improper input validation. The attack may be performed from remote. Upgrading the affected component is advised.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.1",
  "pubDate": "2026-09-17T12:18:29.927Z",
  "pubdate": "2026-09-17T12:18:29.927Z",
  "executiveSummary": "A critical improper input validation vulnerability has been identified within the Quick Security Setup Handler of rcourtman Pulse, affecting versions up to 6.0.4 and 6.1.0-rc.4.\nThe flaw resides within the /api/security/quick-setup endpoint, specifically involving the processing of the Username argument via the fmt.Sprintf function.\nThis vulnerability allows remote, unauthenticated attackers to manipulate input data to potentially bypass security controls or influence application behavior.\nThe impact includes potential unauthorized system interaction or the subversion of internal logic managed by the Quick Security Setup Handler.\nThe risk is significant due to the remote exploitability of the interface, necessitating immediate attention to patching or limiting access to the affected API endpoints.\nNo specific authentication is required to interact with the vulnerable component, increasing the overall threat profile for deployments exposed to untrusted networks.",
  "technicalDetails": "The vulnerability is localized to the /api/security/quick-setup file within the Quick Security Setup Handler component of the Pulse application.\nThe root cause is identified as improper input validation during the handling of the 'Username' argument. The implementation utilizes the Go language function fmt.Sprintf to format strings containing user-supplied input.\nThe reliance on fmt.Sprintf for processing user-controlled input without sufficient sanitization or structural validation creates a vector for input manipulation. In Go, fmt.Sprintf is intended for string formatting and, when fed unchecked external data, can lead to unexpected string concatenation or potential injection scenarios if the resulting output is subsequently parsed by shell commands, database queries, or internal logic routines.\nThe attack flow initiates when a remote actor sends a specially crafted HTTP request to the /api/security/quick-setup endpoint. The attacker provides a malicious payload within the 'Username' parameter. Because the application processes this input via fmt.Sprintf before internal validation logic is fully enforced or while the string is being constructed for configuration, the attacker can influence the state of the Quick Security Setup Handler.\nBy manipulating the 'Username' field, an attacker may exploit the resulting string formation to traverse intended logic paths or inject auxiliary characters that alter the execution flow of the handler. Since this component manages 'Quick Security Setup' configurations, the compromise could allow an attacker to disrupt, misconfigure, or bypass initial security assertions during the setup process.\nThe vulnerability affects all versions of Pulse up to 6.0.4 and 6.1.0-rc.4. The scope of exploitation is limited to the functionality provided by the Quick Security Setup Handler. Post-exploitation impact varies depending on the surrounding code execution environment, but generally includes the ability to interfere with application-level security mechanisms or disrupt service integrity.\nGiven that the handler is accessible remotely, the attack surface is exposed to any network entity capable of reaching the Pulse API. The lack of robust input validation at the application boundary facilitates this unauthorized input processing, highlighting a failure to adhere to secure coding practices regarding user-supplied data handling."
}