Find, fix and prevent vulnerabilities in your code.

Overview

com.h2database:h2 is a database engine

Affected versions of this package are vulnerable to Remote Code Execution (RCE). H2 Console allows loading of custom classes from remote servers through JNDI. This can lead to code execution

If remote access was enabled explicitly and some protection method (such as security constraint) are not set, an intruder can load their own custom class and execute their code in a process using H2 Console (a H2 Server process or a web server with H2 Console servlet).

Note: It should be noted that H2 Console doesn't accept remote connections by default.

Workarounds

• H2 Console should never be available to untrusted users.

• -webAllowOthers is a dangerous setting that should be avoided.

• H2 Console Servlet deployed on a web server can be protected with a security constraint: https://h2database.com/html/tutorial.html#usingH2ConsoleServlet If webAllowOthers is specified, you need to uncomment and edit and as necessary. See documentation of your web server for more details.

All these workaround are mitigatory and unlikely to prevent all attack vectors, upgrade to a fixed version for full remediation.

Remediation

Upgrade com.h2database:h2 to version 2.0.206 or higher.

References

• GItHub Advisory
• GitHub Commit
• The JNDI Strikes Back – Unauthenticated RCE in H2 Database Console

Overview

com.h2database:h2 is a database engine

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection via the org.h2.jdbc.JdbcSQLXML class object, when it receives parsed string data from org.h2.jdbc.JdbcResultSet.getSQLXML() method. If it executes the getSource() method when the parameter is DOMSource.class it will trigger the vulnerability.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

Remediation

Upgrade com.h2database:h2 to version 2.0.202 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR

Overview

com.h2database:h2 is a database engine

Affected versions of this package are vulnerable to Remote Code Execution (RCE). It provides a web console for managing the database, and by default it does not have a password set. The CREATE ALIAS function calls Java code, allowing an attacker to execute arbitrary Java code on projects running the h2 database.

NOTE: To be remotely exploitable, the affected application must be configured with the non-default setting webAllowOthers=true, either in a config file or as a parameter passed in when the servlet is invoked. The vulnerability can be avoided by setting a password on the database and/or restricting access to localhost using the above setting.

PoC

CREATE ALIAS REVERSE AS $$ String reverse(String s) { return new StringBuilder(s).reverse().toString(); } $$;
CALL REVERSE('Test');

Remediation

There is no fixed version for com.h2database:h2.

References

• Datomic Blog
• Datomic Security Advisory
• Exploit DB
• GitHub Issue
• Matheus Bernardes' Blog