CVE-2025-64721 Sandboxie's Integer Overflow in SbieIniServer::RC4Crypt allows sandbox escape and SYSTEM compromise
An integer overflow in Sandboxie allows sandboxed processes to escape isolation and execute arbitrary code with SYSTEM privileges on the host.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-64721?
CVE-2025-64721 is a critical vulnerability in sandboxie-plus Sandboxie, published on 11 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-190
Which versions are affected by CVE-2025-64721?
It affects 1 product.
Products include Sandboxie-Plus Sandboxie.
How do I fix CVE-2025-64721?
No fix has been published for CVE-2025-64721 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-64721 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-64721 exists.
Other vulnerabilities in sandboxie-plus Sandboxie
- CVE-2018-18748 Security feature bypass in n/a
- CVE-2026-34458 Sandboxie-Plus privilege escalation via INI CRLF injection bypassing EditAdminOnly
- CVE-2024-49360 Path traversal in Sandboxie
- CVE-2026-34459 Sandboxie-Plus sandbox escape via uninitialized memory leak and stack overflow in GetRawInputDeviceInfoSlave
- CVE-2026-34464 Sandboxie-Plus NamedPipeServer OpenHandler stack overflow via unterminated server field
Sources
Also known as GHSA-w476-j57g-96vp.