An issue was discovered on Dasan GPON home routers. It is possible to bypass authentication simply by appending "?images" to any URL of the device that requires authentication, as demonstrated by the /menu.html?images/ or /GponForm/diag_FORM?images/ URI. One can then manage the device.
CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.
An issue was discovered on Dasan GPON home routers. It is possible to bypass authentication simply by appending "?images" to any URL of the device that requires authentication, as demonstrated by the /menu.html?images/ or /GponForm/diag_FORM?images/ URI. One can then manage the device.
Confirm exposure before applying a vendor-supported change.
The impacted product is end-of-life and should be disconnected if still in use.
Due date: 2022.04.21Confirm that Dasan Gigabit Passive Optical Network (GPON) Routers and an affected version are present.
Combine exploitation signals with asset exposure and business criticality.
Follow the vendor advisory or supported update path and preserve rollback options.
Recheck the version, service health, access paths, and relevant logs.
