CVE-2026-35078 Overview
CVE-2026-35078 is an arbitrary file deletion vulnerability in the ugw-logstop method. The flaw stems from insufficient validation of user-controlled input passed to the method. A remote attacker holding low-privileged user credentials can delete arbitrary local files on the affected device. The weakness is classified under [CWE-73] (External Control of File Name or Path). CERT-VDE published advisory VDE-2026-039 detailing the issue.
Critical Impact
Authenticated remote attackers can delete arbitrary files, leading to integrity and availability loss across the affected system.
Affected Products
- Products referenced in CERT-VDE Security Advisory VDE-2026-039
- Devices exposing the ugw-logstop management method
- Specific affected versions: refer to vendor advisory
Discovery Timeline
- 2026-06-03 - CVE-2026-35078 published to NVD
- 2026-06-03 - Last updated in NVD database
Technical Details for CVE-2026-35078
Vulnerability Analysis
The ugw-logstop method accepts a parameter that is incorporated into a file path used by a privileged file operation. The method does not validate or canonicalize the supplied value before invoking the deletion routine. An authenticated user can submit a crafted path that resolves to a sensitive system or application file. The underlying process executes the deletion with elevated privileges, allowing the attacker to remove files outside the intended log directory. Deleting configuration files, certificates, or binaries can disable services, break authentication chains, or render the device inoperable.
Root Cause
The root cause is improper enforcement of file path boundaries, mapped to [CWE-73]. The handler trusts the caller-supplied identifier and does not constrain it to an allowlisted directory. There is no canonicalization step to resolve .. traversal sequences or absolute paths. Authorization for the ugw-logstop method is also coarse, granting standard users access to a function that performs filesystem mutation.
Attack Vector
The attack vector is network-based and requires low privileges with no user interaction. An attacker authenticates as a standard user and invokes ugw-logstop with a path pointing to a target file. The service deletes the file on behalf of the attacker. Repeated invocations against critical paths can compromise system integrity and availability. The CERT-VDE advisory describes the issue but does not publish exploitation payloads. See the CERT-VDE Security Advisory for vendor-confirmed technical context.
Detection Methods for CVE-2026-35078
Indicators of Compromise
- Unexpected invocations of the ugw-logstop method in management interface logs from low-privileged accounts
- File deletion events targeting non-log directories such as /etc, configuration stores, or certificate paths
- Service crashes or restart loops following authenticated management activity
- Missing files reported by integrity monitoring shortly after a user session
Detection Strategies
- Audit management API request logs for ugw-logstop calls containing path traversal sequences (.., absolute paths, or null bytes)
- Correlate authenticated session activity with subsequent filesystem deletion events on the device
- Alert on deletions of files outside the expected log directory by the service account running the management interface
Monitoring Recommendations
- Enable verbose logging on the device management interface and forward logs to a centralized SIEM
- Deploy file integrity monitoring on configuration, certificate, and binary directories
- Baseline the normal frequency and parameters of ugw-logstop calls and alert on deviations
How to Mitigate CVE-2026-35078
Immediate Actions Required
- Apply the vendor-supplied update referenced in CERT-VDE advisory VDE-2026-039
- Restrict network access to the device management interface to trusted administrative networks only
- Review and reduce the number of accounts that hold user-level access to the management interface
- Rotate credentials for accounts that may have been exposed to untrusted networks
Patch Information
Consult the CERT-VDE Security Advisory VDE-2026-039 for the authoritative list of fixed firmware or software versions and upgrade instructions. The NVD entry does not enumerate fixed versions; rely on the vendor advisory.
Workarounds
- Place the management interface behind a VPN or jump host to prevent direct network exposure
- Enforce strict role-based access control and remove ugw-logstop privileges from non-administrative roles where configurable
- Monitor and alert on management interface authentication and method invocation patterns until patching is complete
# Example: restrict access to the device management interface via firewall
iptables -A INPUT -p tcp --dport <mgmt-port> -s <admin-subnet> -j ACCEPT
iptables -A INPUT -p tcp --dport <mgmt-port> -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
