CVE-2019-1010208 (published 2019-07-23T14:15Z)

IDRIX, Truecrypt Veracrypt, Truecrypt Prior to 1.23-Hotfix-1 (Veracrypt), all versions (Truecrypt) is affected by: Buffer Overflow. The impact is: Minor information disclosure of kernel stack. The component is: Veracrypt NT Driver (veracrypt.sys). The attack vector is: Locally executed code, IOCTL request to driver. The fixed version is: 1.23-Hotfix-1.

Severity: LOW
CVSS v2 base score: 2.1 (AV:L/AC:L/Au:N/C:P/I:N/A:N)
CVSS v3 base score: 3.3, LOW (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)

Weakness information:
cwe_id: CWE-119
cwe_name: Improper Restriction of Operations within the Bounds of a Memory Buffer
description: The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
extended_description: 
            Certain languages allow direct addressing of memory locations and do not automatically ensure that these locations are valid for the memory buffer that is being referenced. This can cause read or write operations to be performed on memory locations that may be associated with other variables, data structures, or internal program data.
         
         

Fix information:
repo_url: https://github.com/veracrypt/VeraCrypt
commit_details: repo_url: https://github.com/veracrypt/VeraCrypt
author: Mounir IDRASSI
author_date: 2018-09-19 18:26:01+02:00
msg: Windows: fix low severity vulnerability in driver that allowed reading 3 bytes of kernel stack memory (with a rare possibility of 25 additional bytes). Reported by Tim Harrison.
repository: repo_url: https://github.com/veracrypt/VeraCrypt
repo_name: veracrypt/VeraCrypt
description: Disk encryption with strong security based on TrueCrypt
repo_language: C
owner: veracrypt
file_changes: filename: Ntdriver.c
change_type: ModificationType.MODIFY
diff: @@ -1902,11 +1902,24 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 			UNICODE_STRING FullFileName;
 			IO_STATUS_BLOCK IoStatus;
 			LARGE_INTEGER offset;
-			byte readBuffer [TC_SECTOR_SIZE_BIOS];
+			size_t devicePathLen = 0;
 
 			if (!ValidateIOBufferSize (Irp, sizeof (GetSystemDriveConfigurationRequest), ValidateInputOutput))
 				break;
 
+			// check that request->DevicePath has the expected format "\\Device\\HarddiskXXX\\Partition0"
+			if (	!NT_SUCCESS (RtlUnalignedStringCchLengthW (request->DevicePath, TC_MAX_PATH, &devicePathLen))
+				||	(devicePathLen < 28) // 28 is the length of "\\Device\\Harddisk0\\Partition0" which is the minimum
+				||	(devicePathLen > 30) // 30 is the length of "\\Device\\Harddisk255\\Partition0" which is the maximum
+				||	(memcmp (request->DevicePath, L"\\Device\\Harddisk", 16 * sizeof (WCHAR)))
+				||	(memcmp (&request->DevicePath[devicePathLen - 11], L"\\Partition0", 11 * sizeof (WCHAR)))
+				)
+			{
+				Irp->IoStatus.Status = STATUS_INVALID_PARAMETER;
+				Irp->IoStatus.Information = 0;
+				break;
+			}
+
 			EnsureNullTerminatedString (request->DevicePath, sizeof (request->DevicePath));
 			RtlInitUnicodeString (&FullFileName, request->DevicePath);
 
@@ -1918,68 +1931,88 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
 
 			if (NT_SUCCESS (ntStatus))
 			{
-				// Determine if the first sector contains a portion of the VeraCrypt Boot Loader
-				offset.QuadPart = 0;	// MBR
-
-				ntStatus = ZwReadFile (NtFileHandle,
-					NULL,
-					NULL,
-					NULL,
-					&IoStatus,
-					readBuffer,
-					sizeof(readBuffer),
-					&offset,
-					NULL);
-
-				if (NT_SUCCESS (ntStatus))
+				byte *readBuffer = TCalloc (TC_MAX_VOLUME_SECTOR_SIZE);
+				if (!readBuffer)
 				{
-					size_t i;
+					Irp->IoStatus.Status = STATUS_INSUFFICIENT_RESOURCES;
+					Irp->IoStatus.Information = 0;
+				}
+				else
+				{
+					// Determine if the first sector contains a portion of the VeraCrypt Boot Loader
+					offset.QuadPart = 0;	// MBR
 
-					// Check for dynamic drive
-					request->DriveIsDynamic = FALSE;
+					ntStatus = ZwReadFile (NtFileHandle,
+						NULL,
+						NULL,
+						NULL,
+						&IoStatus,
+						readBuffer,
+						TC_MAX_VOLUME_SECTOR_SIZE,
+						&offset,
+						NULL);
 
-					if (readBuffer[510] == 0x55 && readBuffer[511] == 0xaa)
+					if (NT_SUCCESS (ntStatus))
 					{
-						int i;
-						for (i = 0; i < 4; ++i)
+						// check that we could read all needed data
+						if (IoStatus.Information >= TC_SECTOR_SIZE_BIOS)
 						{
-							if (readBuffer[446 + i * 16 + 4] == PARTITION_LDM)
+							size_t i;
+
+							// Check for dynamic drive
+							request->DriveIsDynamic = FALSE;
+
+							if (readBuffer[510] == 0x55 && readBuffer[511] == 0xaa)
 							{
-								request->DriveIsDynamic = TRUE;
-								break;
+								int i;
+								for (i = 0; i < 4; ++i)
+								{
+									if (readBuffer[446 + i * 16 + 4] == PARTITION_LDM)
+									{
+										request->DriveIsDynamic = TRUE;
+										break;
+									}
+								}
 							}
-						}
-					}
 
-					request->BootLoaderVersion = 0;
-					request->Configuration = 0;
-					request->UserConfiguration = 0;
-					request->CustomUserMessage[0] = 0;
+							request->BootLoaderVersion = 0;
+							request->Configuration = 0;
+							request->UserConfiguration = 0;
+							request->CustomUserMessage[0] = 0;
 
-					// Search for the string "VeraCrypt"
-					for (i = 0; i < sizeof (readBuffer) - strlen (TC_APP_NAME); ++i)
-					{
-						if (memcmp (readBuffer + i, TC_APP_NAME, strlen (TC_APP_NAME)) == 0)
-						{
-							request->BootLoaderVersion = BE16 (*(uint16 *) (readBuffer + TC_BOOT_SECTOR_VERSION_OFFSET));
-							request->Configuration = readBuffer[TC_BOOT_SECTOR_CONFIG_OFFSET];
-
-							if (request->BootLoaderVersion != 0 && request->BootLoaderVersion <= VERSION_NUM)
+							// Search for the string "VeraCrypt"
+							for (i = 0; i < sizeof (readBuffer) - strlen (TC_APP_NAME); ++i)
 							{
-								request->UserConfiguration = readBuffer[TC_BOOT_SECTOR_USER_CONFIG_OFFSET];
-								memcpy (request->CustomUserMessage, readBuffer + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, TC_BOOT_SECTOR_USER_MESSAGE_MAX_LENGTH);
+								if (memcmp (readBuffer + i, TC_APP_NAME, strlen (TC_APP_NAME)) == 0)
+								{
+									request->BootLoaderVersion = BE16 (*(uint16 *) (readBuffer + TC_BOOT_SECTOR_VERSION_OFFSET));
+									request->Configuration = readBuffer[TC_BOOT_SECTOR_CONFIG_OFFSET];
+
+									if (request->BootLoaderVersion != 0 && request->BootLoaderVersion <= VERSION_NUM)
+									{
+										request->UserConfiguration = readBuffer[TC_BOOT_SECTOR_USER_CONFIG_OFFSET];
+										memcpy (request->CustomUserMessage, readBuffer + TC_BOOT_SECTOR_USER_MESSAGE_OFFSET, TC_BOOT_SECTOR_USER_MESSAGE_MAX_LENGTH);
+									}
+									break;
+								}
 							}
-							break;
+
+							Irp->IoStatus.Status = STATUS_SUCCESS;
+							Irp->IoStatus.Information = sizeof (*request);
+						}
+						else
+						{
+							Irp->IoStatus.Status = STATUS_INVALID_PARAMETER;
+							Irp->IoStatus.Information = 0;
 						}
 					}
+					else
+					{
+						Irp->IoStatus.Status = ntStatus;
+						Irp->IoStatus.Information = 0;
+					}
 
-					Irp->IoStatus.Status = STATUS_SUCCESS;
-					Irp->IoStatus.Information = sizeof (*request);
-				}
-				else
-				{
-					Irp->IoStatus.Status = ntStatus;
-					Irp->IoStatus.Information = 0;
+					TCfree (readBuffer);
 				}
 
 				ZwClose (NtFileHandle);

programming_language: C++