CyberRota Analysis
AI-GeneratedThe Avast sandbox minifilter driver on Windows is vulnerable due to improper handling of security permissions, allowing low-privileged attackers within the sandbox to escape file isolation and escalate privileges to SYSTEM. This flaw enables attackers to modify security descriptors of virtualized files, potentially accessing sensitive data such as NTLM password hashes. Organizations using affected Windows systems, particularly those relying on Avast for sandboxing, should prioritize patching this vulnerability to mitigate the risk of privilege escalation and data compromise.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Improper preservation of permissions in the Avast sandbox minifilter driver (aswSnx.sys) on Windows allows a local, low-privileged attacker executing inside the sandbox to escape file isolation and escalate to SYSTEM. When the sandbox virtualizes a file it copies the original security descriptor, but the driver opened the virtualization target object with GENERIC_WRITE and FILE_WRITE_ATTRIBUTES only, omitting WRITE_DAC. Every attempt to apply the original DACL therefore failed, and the failure was discarded silently, leaving virtualized copies of sensitive files with permissive permissions. Because the IRP_MJ_CREATE callback additionally did not strip WRITE_DAC for sensitive directories, a sandboxed process could rewrite the security descriptor of a virtualized object, read the virtualized copy of the SAM database, extract local NTLM password hashes and execute code as SYSTEM. The absence of an IRP_MJ_SET_SECURITY callback in the driver's operation registration table is a related defense-in-depth gap, but it is not the control that prevents this attack.