SQL Injection Attacks and Defense - 2009

Recommendations

Info

What Is SQL Injection? • Chapter 1 15 If you were to enter the single-quote character as input to the application, you may be presented with either one of the following errors; the result depends on a number of environmental factors, such as programming language and database in use, as well as protection and defense technologies implemented: Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource You may receive the preceding error or the one that follows. The following error provides useful information on how the SQL statement is being formulated: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''VALUE''' The reason for the error is that the single-quote character has been interpreted as a string delimiter. Syntactically, the SQL query executed at runtime is incorrect (it has one too many string delimiters), and therefore the database throws an exception. The SQL database sees the single-quote character as a special character (a string delimiter). The character is used in SQL injection attacks to “escape” the developer’s query so that the attacker can then construct his own queries and have them executed. The single-quote character is not the only character that acts as an escape character; for instance, in Oracle, the blank space ( ), double pipe (||), comma (,), period (.), (*/), and double-quote characters (“) have special meanings. For example: -- The pipe [|] character can be used to append a function to a value. -- The function will be executed and the result cast and concatenated. http://www.victim.com/id=1||utl_inaddr.get_host_address(local)-- -- An asterisk followed by a forward slash can be used to terminate a -- comment and/or optimizer hint in Oracle http://www.victim.com/hint=*/ from dual-- Incorrectly Handled Types By now, some of you may be thinking that to avoid being exploited by SQL injection, simply escaping or validating input to remove the single-quote character would suffice. Well, that’s a trap which lots of Web application developers have fallen into. As I explained earlier, the single-quote character is interpreted as a string delimiter and is used as the boundary between code and data. When dealing with numeric data, it is not necessary to encapsulate the data within quotes; otherwise, the numeric data would be treated as a string. Here is the source code for a very simple application that passes user input directly to a dynamically created SQL statement. The script accepts a numeric parameter ($userid) and displays information about that user. The query assumes that the parameter will be an integer and so is written without quotes. // build dynamic SQL statement $SQL = "SELECT * FROM table WHERE field = $_GET["userid"]"
16 Chapter 1 • What Is SQL Injection? // execute sql statement $result = mysql_query($SQL); // check to see how many rows were returned from the database $rowcount = mysql_num_rows($result); // iterate through the record set returned $row = 1; while ($db_field = mysql_fetch_assoc($result)) { if ($row
Page 2 and 3: Justin Clarke Lead Author and Techn
Page 4 and 5: Lead Author and Technical Editor Ju
Page 6 and 7: exploiting, and correcting software
Page 8 and 9: Dafydd Stuttard is the author of th
Page 10 and 11: Contents Chapter 1 What Is SQL Inje
Page 12 and 13: Contents xi LAPSE. ................
Page 14 and 15: Contents xiii Generic MySQL Binary
Page 16 and 17: Contents xv Chapter 8 Code-Level De
Page 18 and 19: Contents xvii Increase the Verbosit
Page 20 and 21: Contents xix Ingres Cheat Sheet....
Page 22 and 23: Chapter 1 What Is SQL Injection? So
Page 24 and 25: What Is SQL Injection? • Chapter
Page 30 and 31: execute the query against the datab
Page 38 and 39: Incorrectly Handled Query Assembly
Page 40 and 41: } } reader = cmd.ExecuteReader(); r
Page 50 and 51: Chapter 2 Testing for SQL Injection
Page 52 and 53: Testing for SQL Injection • Chapt
Page 64 and 65: SELECT * FROM products WHERE idprod
Page 86 and 87:
Testing for SQL Injection • Chapt
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Figure 2.15 Exploitation Terminatin
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Time Delays Testing for SQL Injecti
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Summary Testing for SQL Injection
Page 114 and 115:
Page 116 and 117:
Chapter 3 Reviewing Code for SQL In
Page 118 and 119:
Reviewing Code for SQL Injection
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
mssql_bind() − adds a parameter t
Page 130 and 131:
OdbcCommand() − used to construct
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Reviewing PL/SQL and T-SQL Code Rev
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
■■ ■■ ■■ ■■ URL: ht
Page 150 and 151:
■■ ■■ Platform: Windows Pri
Page 152 and 153:
Page 154 and 155:
Summary Reviewing Code for SQL Inje
Page 156 and 157:
Frequently Asked Questions Reviewin
Page 158 and 159:
Chapter 4 Exploiting SQL Injection
Page 160 and 161:
Exploiting SQL Injection • Chapte
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Approach 3: Content-based Exploitin
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Error Messages in Oracle Exploiting
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
MySQL Exploiting SQL Injection •
Page 200 and 201:
Such a query will return output sim
Page 202 and 203:
Page 204 and 205:
SELECT name,spare4 FROM sys.user$ w
Page 206 and 207:
Page 208 and 209:
[+] Bruteforcing the sa password. T
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
select user_name,web_password_raw f
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
HTTP/DNS Exploiting SQL Injection
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Summary Exploiting SQL Injection
Page 238 and 239:
Escalating Privileges Exploiting SQ
Page 240 and 241:
Chapter 5 Blind SQL Injection Explo
Page 242 and 243:
Blind SQL Injection Exploitation
Page 244 and 245:
Page 246 and 247:
Common Blind SQL Injection Scenario
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
1. Is the byte greater than 127? No
Page 254 and 255:
Page 256 and 257:
Using Time-Based Techniques Blind S
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
SELECT * FROM unknowntable UNION SE
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Figure 5.13 Extracting Database Log
Page 286 and 287:
Page 288 and 289:
Summary Blind SQL Injection Exploit
Page 290 and 291:
Page 292 and 293:
Chapter 6 Exploiting the Operating
Page 294 and 295:
Exploiting the Operating System •
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
[operating systems] multi(0)disk(0)
Page 308 and 309:
Figure 6.13 Enabling CLR Integratio
Page 310 and 311:
Oracle Exploiting the Operating Sys
Page 312 and 313:
) c / ) ) ), bfilename('GETPWDIR',
Page 314 and 315:
As expected, this creates sp.txt fi
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
2 443 [+] Calling msfpayload3 to c
Page 322 and 323:
DBMS_ADVISOR is probably the shorte
Page 324 and 325:
EXECUTE IMMEDIATE q'!drop directory
Page 326 and 327:
Microsoft SQL Server Exploiting the
Page 328 and 329:
Page 330 and 331:
Figure 6.22 Creating an UNSAFE Bina
Page 332 and 333:
Page 334 and 335:
Executing Operating System Commands
Page 336 and 337:
Endnotes Exploiting the Operating S
Page 338 and 339:
Chapter 7 Advanced Topics Solutions
Page 340 and 341:
Using Case Variation Advanced Topic
Page 342 and 343:
4. The application URL decodes the
Page 344 and 345:
Advanced Topics • Chapter 7 323 D
Page 346 and 347:
Advanced Topics • Chapter 7 325 I
Page 348 and 349:
Advanced Topics • Chapter 7 327 w
Page 350 and 351:
Advanced Topics • Chapter 7 329 N
Page 352 and 353:
Advanced Topics • Chapter 7 331 m
Page 354 and 355:
Advanced Topics • Chapter 7 333 1
Page 356 and 357:
Using Hybrid Attacks Advanced Topic
Page 358 and 359:
Exploiting Authenticated Vulnerabil
Page 360 and 361:
Advanced Topics • Chapter 7 339
Page 362 and 363:
Chapter 8 Code-Level Defenses Solut
Page 364 and 365:
Code-Level Defenses • Chapter 8 3
Page 366 and 367:
Page 368 and 369:
Page 370 and 371:
END; Execute immediate 'SELECT coun
Page 372 and 373:
Page 374 and 375:
Validating Input in Java Code-Level
Page 376 and 377:
Page 378 and 379:
Page 380 and 381:
Page 382 and 383:
Page 384 and 385:
Page 386 and 387:
Page 388 and 389:
Page 390 and 391:
Page 392 and 393:
UTL_SMTP.HELO(v_connection,'mailhos
Page 394 and 395:
Summary Code-Level Defenses • Cha
Page 396 and 397:
Page 398 and 399:
Chapter 9 Platform-Level Defenses S
Page 400 and 401:
Platform-Level Defenses • Chapter
Page 402 and 403:
Page 404 and 405:
Figure 9.3 Whitelist Rule to Patch
Page 406 and 407:
Page 408 and 409:
Page 410 and 411:
Application Filters Platform-Level
Page 412 and 413:
Page 414 and 415:
Page 416 and 417:
Page 418 and 419:
Use Strong Cryptography to Protect
Page 420 and 421:
Page 422 and 423:
Page 424 and 425:
Page 426 and 427:
Page 428 and 429:
Page 430 and 431:
Page 432 and 433:
Additional Deployment Consideration
Page 434 and 435:
Page 436 and 437:
Chapter 10 References Solutions in
Page 438 and 439:
References • Chapter 10 417 For t
Page 440 and 441:
References • Chapter 10 419 It is
Page 442 and 443:
GROUP BY Statement References • C
Page 444 and 445:
References • Chapter 10 423 you a
Page 446 and 447:
References • Chapter 10 425 Table
Page 448 and 449:
Blind SQL Injection Functions: Micr
Page 450 and 451:
References • Chapter 10 429 the S
Page 452 and 453:
Microsoft SQL Server 2005 Hashes Re
Page 454 and 455:
Page 456 and 457:
References • Chapter 10 435 If MA
Page 458 and 459:
Page 460 and 461:
TYPE oracle_loader DEFAULT DIRECTOR
Page 462 and 463:
References • Chapter 10 441 When
Page 464 and 465:
Page 466 and 467:
Table 10.20 Continued. Troubleshoot
Page 468 and 469:
Enumerating Database Configuration
Page 470 and 471:
Local File Access References • Ch
Page 472 and 473:
References • Chapter 10 451 Infor
Page 474 and 475:
Page 476 and 477:
■■ ■■ ■■ ■■ Referen
Page 478 and 479:
Troubleshooting SQL Injection Attac
Page 480 and 481:
A abstract syntax tree (AST), 125 a
Page 482 and 483:
Index 461 confirming and terminatin
Page 484 and 485:
Index 463 errors application error,
Page 486 and 487:
Index 465 intercepting filters appl
Page 488 and 489:
Index 467 APEX, 196-197 Oracle inte
Page 490 and 491:
Index 469 mysql_query( ) function,
Page 492 and 493:
Index 471 blind SQL injection funct
Page 494:
Index 473 transformation functions,
show all

SQL Injection Attacks and Defense - 2009

Create successful ePaper yourself

Delete template?

Save as template?