Technical disclosures published by independent vulnerability researchers have revealed a patch bypass vulnerability affecting endpoint protective software. The zero-day exploit technique allows local unprivileged process threads to manipulate file hydration scans and achieve elevated SYSTEM privileges on Windows hosts.
The exploit, dubbed ShieldBreak, targets Microsoft Defender components across Windows 10, Windows 11, and Windows Server platforms. ShieldBreak operates as a full patch bypass for previous privilege escalation fixes. By establishing user-mode callback hooks via the Cloud Filter API during Defender cloud-hydration file scanning routines, a local authenticated process can alter file contents in memory while the scan executes, forcing the protective daemon to overwrite protected system binaries and grant root SYSTEM execution rights.
Subverting local endpoint protection daemons compromises host security isolation. Armed with local SYSTEM rights obtained via security engine callback manipulation, local attackers can disable security monitoring agents, unhook kernel sensors, and deploy persistent rootkit implants without triggering alert telemetry.
– Implement endpoint detection queries to monitor Cloud Filter API user-mode callback hook registrations during file hydration scans.
– Restrict local unprivileged user account execution rights and enforce application whitelisting across enterprise workstations.
– Audit local privilege escalation events and file system modification logs associated with antimalware service executables.
– Deploy host-based isolation policies to contain unverified process executions operating under temporary directory paths.
Endpoint protective software resilience demands continuous validation of scan callback routines to ensure antimalware daemons cannot be manipulated for local privilege escalation. #CodeDefence #Microsoft #Defender #ShieldBreak #PrivilegeEscalation #ZeroDay #EndpointSecurity #AppSec
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