CVE-2025-40889 Overview
CVE-2025-40889 is a path traversal vulnerability [CWE-22] affecting the Time Machine functionality in Nozomi Networks Central Management Console (CMC) and Guardian products. The flaw stems from missing validation of two input parameters in a specific request handler. An authenticated user with limited privileges can issue a specifically-crafted request to alter the structure and content of files in the /data folder. The vulnerability also permits attackers to affect file availability, impacting integrity and availability of the appliance.
Critical Impact
Authenticated low-privilege users can manipulate or destroy files in the /data folder of Nozomi CMC and Guardian appliances through crafted Time Machine requests.
Affected Products
- Nozomi Networks Central Management Console (CMC)
- Nozomi Networks Guardian
- Time Machine functionality component (nozominetworks:cmc, nozominetworks:guardian)
Discovery Timeline
- 2025-10-07 - CVE CVE-2025-40889 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-40889
Vulnerability Analysis
The vulnerability resides in the Time Machine feature of Nozomi Networks CMC and Guardian. Time Machine handles configuration and state snapshots used for operational rollback and forensic review. Two request parameters accepted by this feature lack proper input validation. An authenticated attacker can supply traversal sequences such as ../ within these parameters to escape the intended working directory.
The vulnerability is classified under [CWE-22] Improper Limitation of a Pathname to a Restricted Directory. The EPSS probability is 0.37%. Because the issue requires authentication but only low privileges, any user account on the appliance becomes a viable launchpad for exploitation. The impact is limited to integrity and availability — confidentiality is not affected.
Root Cause
The root cause is missing canonicalization and validation of two user-controlled input parameters passed to the Time Machine handler. The application concatenates these parameters into file system paths under the /data directory without rejecting traversal characters, absolute paths, or sequences that resolve outside the intended scope. The component trusts authenticated input rather than enforcing a strict allowlist of permitted file names.
Attack Vector
Exploitation requires network access to the management interface and valid credentials for a low-privilege user. The attacker sends a crafted HTTP request to the Time Machine endpoint with traversal payloads in the vulnerable parameters. The server resolves the manipulated path and writes, overwrites, or removes files within the /data folder. Successful exploitation can corrupt operational data, destroy snapshots, or render the appliance unable to serve monitoring functions for industrial control system environments.
No public proof-of-concept has been published. Refer to the Nozomi Networks Security Advisory NN-2025:9-01 for vendor technical details.
Detection Methods for CVE-2025-40889
Indicators of Compromise
- HTTP requests to Time Machine endpoints containing ../, ..\, URL-encoded variants (%2e%2e%2f), or absolute path prefixes in request parameters
- Unexpected file modifications, deletions, or creations within the /data directory of CMC or Guardian appliances
- Authentication events from low-privilege accounts immediately preceding anomalous file system activity
- Time Machine snapshot integrity errors or missing snapshot artifacts
Detection Strategies
- Inspect web server and application logs on CMC and Guardian appliances for requests targeting Time Machine routes with traversal sequences
- Correlate authenticated user sessions with file system audit events on /data
- Monitor for HTTP 200 responses to Time Machine requests originating from non-administrative accounts
Monitoring Recommendations
- Forward appliance audit logs to a centralized SIEM and alert on path traversal patterns in request parameters
- Establish a file integrity baseline for the /data folder and alert on unauthorized modifications
- Review user privilege assignments on CMC and Guardian and flag accounts performing administrative-equivalent actions from low-privilege roles
How to Mitigate CVE-2025-40889
Immediate Actions Required
- Apply the fixed versions of CMC and Guardian as listed in the Nozomi Networks Security Advisory
- Restrict network access to CMC and Guardian management interfaces to trusted administrative networks only
- Audit existing user accounts and remove or reduce privileges for accounts that do not require Time Machine access
- Rotate credentials for any low-privilege accounts that may have been exposed
Patch Information
Nozomi Networks has published advisory NN-2025:9-01 describing the affected versions and the patched releases. Administrators should consult the Nozomi Networks Security Advisory to identify the fixed build for their deployment and schedule an upgrade. There are no vendor-confirmed reports of in-the-wild exploitation, and the CVE is not listed in the CISA Known Exploited Vulnerabilities catalog.
Workarounds
- Limit access to the Time Machine functionality through network segmentation and firewall rules on the management plane
- Enforce strict role-based access control and avoid issuing low-privilege accounts to users who do not require appliance access
- Increase logging verbosity on the management interface to capture parameter contents for forensic review until patching is complete
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
