Executive Summary

CVE-2026-34527 is a vulnerability in Sandboxie-Plus, an open source sandbox isolation software for Windows. The issue lies in the function SbieIniServer::HashPassword, which incorrectly converts a SHA-1 digest to a hexadecimal string. Specifically, the high nibble of each byte is shifted right by 8 bits instead of 4, causing the high nibble to always be zero.

This mistake reduces the effective entropy of the stored password hash from 160 bits to 80 bits, making the password hashes significantly easier to brute-force. Additionally, the hashing scheme uses an unsalted SHA-1, which is already considered weak for password storage.

The vulnerability affects Sandboxie versions up to 1.17.2 and has been fixed in version 1.17.3 by correcting the bitwise operation and recommending the use of stronger, salted hashing algorithms.

Useful 0 Not Useful 0

Compliance Impact

The vulnerability reduces the effective entropy of stored password hashes from 160 bits to 80 bits due to an incorrect bitwise operation and the use of an unsalted SHA-1 hash. This weakened cryptographic protection makes password hashes materially easier to brute-force.

While the provided information does not explicitly mention compliance with standards like GDPR or HIPAA, weakened password hashing can increase the risk of unauthorized access to sensitive data, which may impact compliance with data protection regulations that require strong security controls.

To address this, the fix involves correcting the hashing method and adopting stronger, salted hashing algorithms such as PBKDF2, scrypt, or Argon2, which would better align with security best practices recommended by many compliance frameworks.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability reduces the security of stored password hashes by lowering their entropy, making them easier to crack through brute-force attacks.

If an attacker obtains leaked or backed-up password hashes from affected versions of Sandboxie-Plus, they can more easily guess the original passwords offline.

This weakened protection increases the risk of unauthorized access to sandboxed environments or other systems relying on these passwords.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability is related to the incorrect conversion of SHA-1 password hashes within Sandboxie-Plus versions 1.17.2 and earlier. Detection involves identifying if your system is running an affected version of Sandboxie-Plus and if stored password hashes are generated by the vulnerable hashing function.

Since this is a local software issue rather than a network-based vulnerability, detection commands would focus on verifying the installed version of Sandboxie-Plus and inspecting stored password hashes for the weak hash format.

• Check the installed Sandboxie-Plus version to see if it is 1.17.2 or earlier.
• On Windows, use PowerShell to check the installed version, for example: `Get-ItemProperty 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*' | Where-Object { $_.DisplayName -like '*Sandboxie-Plus*' } | Select-Object DisplayName, DisplayVersion`
• Locate and examine the stored password hash files or configuration files where EditPassword hashes are stored to identify if they use the vulnerable hash format (low nibble only).

No specific network commands or scanning tools are mentioned for detecting this vulnerability, as it is a local cryptographic implementation flaw.

Useful 0 Not Useful 0

Mitigation Strategies

The primary mitigation step is to upgrade Sandboxie-Plus to version 1.17.3 or later, where the hashing bug has been fixed.

After upgrading, migrate existing stored password hashes to the new, corrected hashing scheme to restore full entropy and security.

Consider adopting a more secure password hashing scheme such as PBKDF2, scrypt, or Argon2, which includes salting and is resistant to brute-force attacks.

Avoid using the vulnerable versions (1.17.2 and earlier) to prevent exposure to easier brute-force attacks on password hashes.

Useful 0 Not Useful 0