CVE-2026-8170 in ExtremeXOS
Summary
by MITRE • 07/20/2026
The mv, cp, and rm file utilities exposed within the ExtremeXOS (EXOS) shell environment fail to safely canonicalize paths and follow symbolic links outside of the intended privilege boundary. An attacker with low-privilege CLI access can create a symbolic link that references a privileged filesystem location and then invoke the affected utilities to read, modify, or replace security-critical files outside of their authorized scope. Under certain conditions, this may enable escalation to root-level access and persistent modification of the device software stack. Exploitation is possible remotely by an attacker holding a low-privilege account, or locally via the serial console.
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Analysis
by VulDB Data Team • 07/20/2026
This vulnerability represents a critical path traversal flaw in ExtremeXOS network device firmware that stems from improper path canonicalization within core file manipulation utilities. The affected commands mv cp and rm fail to adequately validate or sanitize symbolic link references during execution, creating a privilege escalation vector that allows low-privileged users to access restricted filesystem areas. This weakness directly maps to CWE-22 Path Traversal vulnerabilities where insufficient input validation permits unauthorized access to protected resources through carefully crafted symbolic links. The vulnerability exists within the EXOS shell environment which operates with elevated privileges for these utilities, making the flaw particularly dangerous as it bypasses normal access controls that should prevent unauthorized file operations.
The technical exploitation occurs when an attacker with basic CLI access creates a symbolic link pointing to a privileged location such as configuration files or system binaries within the device filesystem. When the vulnerable utilities execute against this crafted symlink, they follow the link and operate on the target file rather than the intended source, effectively enabling arbitrary file manipulation beyond the user's authorized scope. This behavior violates fundamental security principles of least privilege and proper access control enforcement that should be maintained even within privileged execution contexts. The vulnerability affects both remote CLI sessions and local serial console access, providing multiple attack vectors for exploitation and demonstrating the broad impact across different operational interfaces.
The operational impact of this vulnerability extends beyond simple file access to encompass full system compromise potential including root-level privilege escalation and persistent modification of device software components. Attackers can leverage this flaw to modify critical system files such as configuration databases, firmware images, or authentication mechanisms, potentially leading to complete device takeover. The ability to perform remote exploitation without requiring physical access significantly increases the threat surface and attack surface complexity for network administrators. This vulnerability directly aligns with ATT&CK technique T1059 Command and Scripting Interpreter where attackers use legitimate system utilities to execute malicious operations, combined with T1548.003 Abuse of Functionality to leverage existing privileged tools for unauthorized access.
Mitigation strategies should focus on immediate firmware updates from Extreme Networks that address the path canonicalization issues in the affected utilities. Network administrators must implement strict access controls limiting CLI access to only authorized personnel and consider disabling unnecessary file manipulation capabilities where possible. System monitoring should be enhanced to detect suspicious symbolic link creation patterns and unusual file operations that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and privilege separation within embedded systems, highlighting requirements from security standards such as NIST SP 800-53 and ISO/IEC 27001 that mandate secure coding practices for system utilities operating in privileged contexts. Regular security assessments of device firmware and access controls should be conducted to identify similar vulnerabilities in other system components that may present comparable risks to network infrastructure security.