ExtremeXOS (EXOS) uses a challenge-response mechanism to authorize access to the privileged debug-mode function. The challenge value is generated using an insufficiently random source, which under certain conditions may allow an attacker to predict the expected response and activate debug-mode without authorization. Depending on device configuration and version, this may enable escalation to root-level access and persistent modification of the device software stack. Exploitation requires either a valid low-privilege account on the device (remote scenario) or physical serial console access (local scenario). This vulnerability is distinct from CVE-2017-14329, which addressed a different issue involving Python script privileges.
Extreme would like to thank Hadrien Barral (Université Gustave Eiffel) and Georges-Axel Jaloyan (French Ministry of the Interior) for responsible disclosure of their findings.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:HVI:HVA:HSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NOther