CVE-2025-64721

CRITICAL
Published Dec 11, 2025 Modified Dec 22, 2025 CWE-190

Description

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.

CVSS v3.1 Score

10.0
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weakness Type (CWE)

CWE-190 Integer Overflow

Affected Products

Vendor Product
sandboxie-plus sandboxie

References

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 10.0 (CRITICAL).
How severe is CVE-2025-64721? +
CVE-2025-64721 has a CVSS v3.1 score of 10.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.
What products are affected by CVE-2025-64721? +
CVE-2025-64721 affects products from sandboxie-plus, specifically: sandboxie. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2025-64721? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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