Sandboxie Plus: community verdicts

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, an INI injection vulnerability allows any standard local user to bypass configuration restrictions (EditAdminOnly and ConfigPassword) and inject arbitrary directives into the global Sandboxie.ini configuration file. The background service skips authorization checks for IPC messages targeting sections beginning with UserSettings_, but does not sanitize CRLF characters in either the value parameter (via MSGID_SBIE_INI_ADD_SETTING) or the setting name parameter (via MSGID_SBIE_INI_SET_SETTING). An attacker can inject a new sandbox section header with unrestricted permissions, enabling sandbox escape and SYSTEM privilege escalation. This issue has been fixed in version 1.17.3.

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, NamedPipeServer::OpenHandler copies the server field from NAMED_PIPE_OPEN_REQ into a fixed WCHAR pipename[160] stack buffer using wcscat without verifying null termination. The handler only enforces a minimum packet size, and since the service pipe accepts variable-length messages, a sandboxed caller can fill the server[48] field with non-zero data and append additional controlled wide characters after the structure. wcscat then reads past the fixed field and overflows the stack buffer in the SYSTEM service. This message is restricted to sandboxed callers, making it a sandbox escape vector. This can lead to a crash of the SbieSvc service or potential code execution as SYSTEM. This issue has been fixed in version 1.17.3.

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, several ProcessServer handlers (KillAllHandler, SuspendAllHandler, and RunSandboxedHandler) copy a WCHAR boxname[34] field from request structures into WCHAR[40] stack buffers using wcscpy without verifying null termination. Because the service pipe accepts variable-length packets larger than the request structure, an attacker can fill the boxname field with non-zero data and append additional controlled wide characters after the structure. wcscpy then reads past the fixed field and overflows the destination stack buffer. The service pipe is created with a NULL DACL, allowing any local process to connect, and the unsafe copy occurs before authorization checks. This can lead to a crash of the SbieSvc service or potential code execution as SYSTEM. This issue has been fixed in version 1.17.3.

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, the SbieIniServer RunSbieCtrl handler contains a stack buffer overflow. The MSGID_SBIE_INI_RUN_SBIE_CTRL message is handled before normal sandbox and impersonation checks, and for non-sandboxed callers, the handler copies the trailing message payload into a fixed-size WCHAR ctrlCmd[128] stack buffer using memcpy without verifying the length fits within the buffer. The service pipe is created with a NULL DACL, allowing any local interactive process to connect and send an oversized payload to overflow the stack. This can lead to a crash of the SbieSvc service or potential code execution as SYSTEM. This issue has been fixed in version 1.17.3.

Sandboxie is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, a local denial of service vulnerability exists in the Sandboxie kernel driver. An unprivileged process running inside a Standard Sandbox can send a malformed IOCTL to the \Device\SandboxieDriverApi driver, triggering an immediate kernel crash (BSOD). The vulnerability affects the Standard Sandbox configuration both with and without dropped administrator privileges, but does not affect the Security Hardened Sandbox configuration. This issue has been fixed in version 1.17.3. Users who cannot update can use the Security Hardened Sandbox configuration as a workaround.

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, the SbieSvc proxy service's GetRawInputDeviceInfoSlave handler contains two vulnerabilities that can be chained for sandbox escape. First, when a sandboxed process sends an IPC request with cbSize set to 0, up to 32KB of uninitialized stack memory from the service process is returned, leaking return addresses and stack cookies which bypass ASLR and /GS protections. Second, the handler performs a memcpy with an attacker-controlled length without verifying it fits within the 32KB stack buffer, enabling a stack buffer overflow. By chaining the information leak with the overflow, a sandboxed process can execute a ROP chain to achieve SYSTEM privilege escalation, even from a Security Hardened Sandbox. Hardware-enforced shadow stacks (Intel CET) prevent the ROP chain execution but do not mitigate the information leak. This issue has been fixed in version 1.17.3.

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, a Time-of-Check-to-Time-of-Use (TOCTOU) race condition exists during addon installation. When a user installs an addon through the SandMan interface, UpdUtil.exe is spawned as SYSTEM by SbieSvc but stages files in the user-writable %TEMP%\sandboxie-updater directory. After UpdUtil verifies file hashes against the signed addon manifest, install.bat extracts files.cab and executes config.exe from its contents. Between hash verification and extraction, an unprivileged user can replace files.cab with a crafted cabinet containing a malicious executable, which is then run as SYSTEM. No UAC prompt is required. This issue has been fixed in version 1.17.3.

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, SbieIniServer::HashPassword converts a SHA-1 digest to hexadecimal incorrectly. The high nibble of each byte is shifted right by 8 instead of 4, which always produces zero for an 8-bit value. As a result, the stored EditPassword hash only preserves the low nibble of each digest byte, reducing the effective entropy from 160 bits to 80 bits. This is layered on top of an unsalted SHA-1 scheme. The reduced entropy makes leaked or backed-up password hashes materially easier to brute-force. This issue has been fixed in version 1.17.3.