By exploitdb papers bot•November 21, 2006•
papers
Seditio 1.10 Avatar Select SQL Injection Explained
Seditio 1.10 Avatar Select SQL Injection Explained
What this paper is
This paper details a SQL injection vulnerability found in Seditio version 1.10. Specifically, it targets the avatarselect functionality within the user profile section. The vulnerability allows a logged-in attacker to modify user data, such as changing a user's password, by injecting malicious SQL code into the id parameter.
Simple technical breakdown
The vulnerability exists because the web application doesn't properly sanitize user input before using it in a database query. In this case, the id parameter, which is expected to contain a filename for an avatar, is directly incorporated into an SQL statement. By providing specially crafted input, an attacker can trick the database into executing unintended commands.
The exploit works by appending SQL code to the legitimate id value. This appended code can then alter the original SQL query, leading to actions like updating user credentials. The attacker needs to be logged into the Seditio application to exploit this.
Complete code and payload walkthrough
The provided text doesn't contain executable code or shellcode in the traditional sense. Instead, it provides example URLs demonstrating how the vulnerability is triggered and what the injected payload looks like.
Let's break down the example URLs and the injected SQL:
Example 1: Triggering the vulnerability
GET -> http://www.victim.com/users.php?m=profile&a=avatarselect&x=XVALUE&id=default.gif[SQL Inject]http://www.victim.com/users.php: This is the target script.m=profile: Specifies the module or section of the application.a=avatarselect: Indicates the action to be performed, which is selecting an avatar.x=XVALUE: This parameter is described as "special to every user in Seditio" and is part of the legitimateavatarselectlink. Its exact purpose and value are unknown without the Seditio source code, but it's likely a unique identifier or token.id=default.gif[SQL Inject]: This is the critical parameter.default.gifis likely the expected value (a default avatar filename).[SQL Inject]signifies where the attacker would insert their malicious SQL code.
Example 2: The actual exploit payload
GET -> http://www.victim.com/users.php?m=profile&a=avatarselect&x=011A99&id=default.gif%2500%2527,user_password=%2527e10adc3949ba59abbe56e057f20f883e%2527/**/where/**/user_id=1/*Let's decode the URL-encoded parts:
%2500: This decodes to%00, which is a null byte. In some contexts, null bytes can terminate strings, potentially bypassing certain input filters.%2527: This decodes to%27, which is a single quote ('). This is the primary character used to break out of the SQL string context.e10adc3949ba59abbe56e057f20f883e: This is a hexadecimal string. The paper states that with this, "remote attacker changes password of 1st user of Seditio to 123456". This implies thate10adc3949ba59abbe56e057f20f883eis the MD5 hash for the password "123456"./**/: This is a common way to insert comments in SQL. It can be used to bypass simple keyword filters or to add whitespace where it might not be expected.%2527: Decodes to%27, a single quote (').
Now, let's reconstruct the injected SQL by looking at the id parameter:
default.gif%00%27,user_password=%27e10adc3949ba59abbe56e057f20f883e%27/**/where/**/user_id=1/*
Assuming the original query looked something like this (this is an educated guess based on the exploit):
UPDATE users SET avatar = 'default.gif' WHERE user_id = 'XVALUE';The injected payload modifies this query. The attacker is likely trying to achieve something like this:
UPDATE users SET avatar = 'default.gif' /* original part, possibly truncated by null byte */, user_password = 'e10adc3949ba59abbe56e057f20f883e' WHERE user_id = 1 /* rest of the query */Mapping of code fragment/block to practical purpose:
default.gif: The original, expected value for theidparameter.%2500(%00): Null byte. Likely used to terminate the original string value ofavataror to bypass filters.%2527(%27): Single quote. Used to close the string literal for theavatarfield and to start injecting new SQL.,user_password=%27...%27: This part injects a new assignment for theuser_passwordcolumn. The single quotes enclose the new password hash.e10adc3949ba59abbe56e057f20f883e: The MD5 hash for the new password ("123456")./**/where/**/user_id=1: This injects theWHEREclause to target a specific user (user ID 1). The/**/are SQL comments used for obfuscation or to bypass filters./*: This starts a SQL comment, effectively commenting out any remaining part of the original query that might have followed.
Payload stages:
This exploit doesn't have distinct shellcode stages. It's a direct SQL injection that manipulates an existing database query. The "payload" is the crafted string appended to the id parameter, which, when interpreted by the SQL server, results in a password update.
Practical details for offensive operations teams
- Required Access Level: Authenticated user within the Seditio application. This is not a remote unauthenticated exploit.
- Lab Preconditions:
- A running instance of Seditio version 1.10 or earlier.
- A valid user account with login credentials for the target Seditio instance.
- Knowledge of the target user's
user_id(in this case, it's assumed to be1). If theuser_idis unknown, enumeration might be required, or the attacker might try common IDs. - The
avatarselectfunctionality must be accessible and enabled for the authenticated user.
- Tooling Assumptions:
- A web browser for manual testing or crafting requests.
- A web proxy (e.g., Burp Suite, OWASP ZAP) to intercept and modify requests.
- An SQL client or database access tool might be useful for verifying the password change (if possible) or for understanding the database schema.
- A tool to generate MD5 hashes for passwords (e.g.,
md5sum, online hash generators) if a different password is to be set.
- Execution Pitfalls:
- Input Sanitization/WAFs: Modern Web Application Firewalls (WAFs) or more robust input sanitization in later Seditio versions or custom code could detect and block the injected SQL syntax (e.g., single quotes,
UNION,/**/). - Database Specifics: The exact SQL syntax might need minor adjustments based on the underlying database system (e.g., MySQL, PostgreSQL, SQL Server) Seditio is using. The example implies a MySQL-like syntax.
XVALUEParameter: IfXVALUEis not simply passed through but validated or used in a way that prevents injection (e.g., as a prepared statement parameter), the exploit might fail. The paper states it's "special to every user," suggesting it might be an ID or token that is not directly part of the SQL query being injected into.- Null Byte Handling: The effectiveness of the null byte (
%00) depends on how the application handles string termination and how the database driver processes the input. - User ID: If the target user ID is not
1, the exploit needs to be modified. - Authentication Token/Session: The attacker must maintain their authenticated session throughout the exploit attempt.
- Input Sanitization/WAFs: Modern Web Application Firewalls (WAFs) or more robust input sanitization in later Seditio versions or custom code could detect and block the injected SQL syntax (e.g., single quotes,
- Telemetry:
- Web Server Logs: Look for unusual GET requests to
users.phpwith them=profile,a=avatarselectparameters, and a modifiedidparameter containing SQL injection patterns. - Database Logs: Monitor for unusual UPDATE statements targeting the
userstable, specifically theuser_passwordcolumn. Look for queries that deviate from expected patterns, especially those involving string manipulation andWHEREclauses that might be dynamically constructed. - Application Logs: Seditio's own logs might record errors if the injected SQL causes an unexpected database exception.
- User Reports: Users reporting unexpected password changes or inability to log in.
- Web Server Logs: Look for unusual GET requests to
Where this was used and when
- Approximate Year: 2006. The paper was published on November 21, 2006.
- Context: This vulnerability would have been relevant to administrators and users of Seditio 1.10, a content management system or similar web application framework popular around that time. It's a classic example of a SQL injection flaw in a PHP web application.
Defensive lessons for modern teams
- Input Validation is Paramount: Never trust user input. All data received from the client (GET parameters, POST data, cookies, headers) must be treated as potentially malicious.
- Parameterized Queries (Prepared Statements): This is the most effective defense against SQL injection. Instead of building SQL strings with user input, use parameterized queries where the SQL structure is defined separately from the data. The database engine then treats the input strictly as data, not executable code.
- Least Privilege: Ensure the database user account used by the web application has only the minimum necessary privileges. If the web application only needs to read user data, it shouldn't have UPDATE or DELETE permissions on sensitive tables like
users. - WAFs: While not a silver bullet, Web Application Firewalls can help detect and block common SQL injection patterns. However, they can be bypassed by sophisticated attackers.
- Regular Patching and Updates: Keep all software, including web applications and their underlying frameworks, up to date with the latest security patches.
- Secure Coding Practices: Train developers on secure coding principles, including how to avoid common vulnerabilities like SQL injection.
- Error Handling: Avoid revealing detailed database error messages to end-users, as these can provide valuable information to attackers.
ASCII visual (if applicable)
This exploit is a direct manipulation of a web request and its impact on a database query. A visual representation of the request flow is most appropriate.
+-----------------+ +-----------------+ +-----------------+ +-----------------+
| Attacker's | ---> | Web Browser/ | ---> | Web Server | ---> | Database Server |
| Machine | | Proxy | | (Seditio App) | | |
+-----------------+ +-----------------+ +-----------------+ +-----------------+
| | |
| 1. Craft Malicious GET Request | |
| (e.g., with injected SQL in 'id') | |
| | |
+---------------------------------------------------+ |
|
| 2. Parse Request
| (SQL Query
| Construction)
|
| 3. Execute Modified
| SQL Query
| (e.g., UPDATE user_password)
|
| 4. Return Results
+---------------->Source references
- Paper URL: https://www.exploit-db.com/papers/2820
- Raw URL: https://www.exploit-db.com/raw/2820
- Original Advisory (referenced in paper): http://www.nukedx.com/?viewdoc=52
Original Exploit-DB Content (Verbatim)
Seditio <= 1.10 Remote SQL Injection (avatarselect id) Vulnerability
Discovered by: nukedx
Contacts: ICQ: 10072 MSN/Mail: nukedx@nukedx.com web: http://www.nukedx.com
Original advisory can be found at: http://www.nukedx.com/?viewdoc=52
----
GET -> http://www.victim.com/users.php?m=profile&a=avatarselect&x=XVALUE&id=default.gif[SQL Inject]
GET -> http://www.victim.com/users.php?m=profile&a=avatarselect&x=011A99&id=default.gif%2500%2527,user_password=%2527e10adc3949ba59abbe56e057f20f883e%2527/**/where/**/user_id=1/* with this example remote attacker changes password of 1st user of Seditio to 123456
The XVALUE is comes with your avatarselect link it's special to everyuser in Seditio.
For using this vulnerability you must be logged in to Seditio...
# nukedx.com [2006-11-21]
# milw0rm.com [2006-11-21]