Integer overflow in Sandboxie-Plus Sandboxie

CVE-2025-64721

Sandboxie is a sandbox-based isolation software for 32-bit and 64-bit Windows NT-based operating systems. In versions 1.16.6 and below, the SYSTEM-level service SbieSvc.exe exposes SbieIniServer::RC4Crypt to sandboxed processes. The handler adds a fixed header size to a caller-controlled value_len without overflow checking. A large value_len (e.g., 0xFFFFFFF0) wraps the allocation size, causing a heap overflow when attacker data is copied into the undersized buffer. This allows sandboxed processes to execute arbitrary code as SYSTEM, fully compromising the host. This issue is fixed in version 1.16.7.

Vulnerability class: Integer Overflow

EPSS: 0.007 (51.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-64721?
CVE-2025-64721 is a critical-severity vulnerability in Sandboxie-Plus Sandboxie, classified under Integer Overflow or Wraparound. CVSS score: 10.0/10. Published 2025-12-11.
How severe is CVE-2025-64721?
Critical severity. CVSS v3 base score is 10.0 out of 10.