diff options
| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2025-01-11 23:22:40 +0100 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2025-01-14 14:59:45 +0100 |
| commit | 078d1410dd3307956638d9c90f40ec15032ef01f (patch) | |
| tree | 5b1bba6f7d7e9509a14642d9182b518ba40c8a2c /src/Core/Unix/CoreUnix.cpp | |
| parent | 2cca2e1dafa405addc3af8724baf8563f352ac1c (diff) | |
| download | VeraCrypt-078d1410dd3307956638d9c90f40ec15032ef01f.tar.gz VeraCrypt-078d1410dd3307956638d9c90f40ec15032ef01f.zip | |
Linux/FreeBSD: Prevent mounting volumes on system directories and PATH (CVE-2025-23021, reported by SivertPL @__tfr)
Added security checks to prevent mounting VeraCrypt volumes on system directories (like /usr/bin) or directories in the user's PATH, which could theoretically allow execution of malicious binaries instead of legitimate system binaries.
Key changes:
- Block mounting on protected system directories (/usr, /bin, /lib, etc.)
This restriction cannot be overridden
- Block mounting on directories present in user's PATH environment variable
This can be overridden with --allow-insecure-mount flag
- Add visual warnings (red border, "[INSECURE MODE]") when mounting on PATH directories is allowed
- Handle symlinks properly when checking paths
- Add new error messages for blocked mount points
To override PATH-based restrictions only (system directories remain protected):
veracrypt --allow-insecure-mount [options] volume mountpoint
Security Impact: Low to Medium
The attack requires either:
- User explicitly choosing a system directory as mount point instead of using VeraCrypt's default mount points
- Or attacker having both filesystem access to modify favorites configuration AND knowledge of the volume password
Default mount points are not affected by this vulnerability.
Security: CVE-2025-23021
Diffstat (limited to 'src/Core/Unix/CoreUnix.cpp')
| -rw-r--r-- | src/Core/Unix/CoreUnix.cpp | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/Core/Unix/CoreUnix.cpp b/src/Core/Unix/CoreUnix.cpp index f6827806..1f2d3125 100644 --- a/src/Core/Unix/CoreUnix.cpp +++ b/src/Core/Unix/CoreUnix.cpp @@ -596,6 +596,17 @@ namespace VeraCrypt if (IsVolumeMounted (*options.Path)) throw VolumeAlreadyMounted (SRC_POS); + if (options.MountPoint && !options.MountPoint->IsEmpty()) + { + // Reject if the mount point is a system directory + if (IsProtectedSystemDirectory(*options.MountPoint)) + throw MountPointBlocked (SRC_POS); + + // Reject if the mount point is in the user's PATH and the user has not explicitly allowed insecure mount points + if (!GetAllowInsecureMount() && IsDirectoryOnUserPath(*options.MountPoint)) + throw MountPointNotAllowed (SRC_POS); + } + Cipher::EnableHwSupport (!options.NoHardwareCrypto); shared_ptr <Volume> volume; @@ -828,4 +839,100 @@ namespace VeraCrypt s << GetDefaultMountPointPrefix() << slotNumber; return s.str(); } + + bool CoreUnix::IsProtectedSystemDirectory (const DirectoryPath &directory) const + { + static const char* systemDirs[] = { + "/usr", + "/bin", + "/sbin", + "/lib", +#ifdef TC_LINUX + "/lib32", + "/lib64", + "/libx32", +#endif + "/etc", + "/boot", + "/root", + "/proc", + "/sys", + "/dev", + NULL + }; + + // Resolve any symlinks in the path + string path(directory); + char* resolvedPathCStr = realpath(path.c_str(), NULL); + if (resolvedPathCStr) + { + path = resolvedPathCStr; + free(resolvedPathCStr); // Free the allocated memory + } + + // reject of the path is the root directory "/" + if (path == "/") + return true; + + // Check if resolved path matches any system directory + for (int i = 0; systemDirs[i] != NULL; ++i) + { + if (path == systemDirs[i] || path.find(string(systemDirs[i]) + "/") == 0) + return true; + } + + return false; + } + + bool CoreUnix::IsDirectoryOnUserPath(const DirectoryPath &directory) const + { + // Obtain the PATH environment variable + const char* pathEnv = UserEnvPATH.c_str(); + if (!pathEnv[0]) + return false; + + // Resolve the given directory + string dirPath(directory); + char* resolvedDir = realpath(dirPath.c_str(), NULL); + if (resolvedDir) + { + dirPath = resolvedDir; + free(resolvedDir); + } + + // Split PATH and compare each entry + stringstream ss(pathEnv); + string token; + while (getline(ss, token, ':')) + { + // remove any trailing slashes from the token + while (!token.empty() && token.back() == '/') + token.pop_back(); + + if (token.empty()) + continue; + + // check if the directory is the same as the entry or a subdirectory + if (dirPath == token || dirPath.find(token + "/") == 0) + return true; + + // handle the case where the PATH entry is a symlink + char* resolvedEntry = realpath(token.c_str(), NULL); + if (!resolvedEntry) + continue; // skip to the next entry since the path does not exist + + string entryPath(resolvedEntry); + free(resolvedEntry); + + // remove any trailing slashes from the token + while (!entryPath.empty() && entryPath.back() == '/') + entryPath.pop_back(); + + // perform check again if the resolved path is different from the original (symlink) + if (dirPath == entryPath || dirPath.find(entryPath + "/") == 0) + return true; + } + + return false; + } } |