CVE-2023-44483: Private Key Disclosure Vulnerability in Apache Santuario - XML Security for Java (Versions Prior to 2.2.6, 2.3.4, and 3..3) Using JSR 105 API

INTRODUCTION

A significant vulnerability (CVE-2023-44483) has been discovered in Apache Santuario - XML Security for Java that impacts all its versions prior to 2.2.6, 2.3.4, and 3..3 when using the JSR 105 API. This issue leads to the potential disclosure of a private key in log files when generating an XML Signature and logging with the debug level is enabled. To mitigate this vulnerability, users are advised to upgrade to version 2.2.6, 2.3.4, or 3..3.

EXPLOIT DETAILS

The risks associated with this vulnerability include the exposure of sensitive data, which could give attackers access to private encryption keys. The vulnerability can be exploited when logging is enabled at the debug level and the application generates XML Signatures using the JSR 105 API. The attack vector is through log files, which may inadvertently contain the private key.

Apache Santuario is a popular library used for processing and signing XML and is commonly used in web services and other XML-based communication systems. The vulnerability affects a wide range of applications, including those that do not use encryption directly, due to the fact that the library may be a dependency of other libraries or applications.

CODE SNIPPET

The disclosure of a private key in log files occurs when an XML Signature is generated using the JSR 105 API in affected versions of Apache Santuario. The following code snippet demonstrates the vulnerable functionality:

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.crypto.dsig.XMLSignatureFactory;
import javax.xml.crypto.dsig.keyinfo.KeyInfoFactory;
import javax.xml.crypto.dsig.keyinfo.X509Data;

// ...

private void generateXMLSignature() {
    try {
        XMLSignatureFactory signatureFactory = XMLSignatureFactory.getInstance("DOM");
        KeyInfoFactory kif = signatureFactory.getKeyInfoFactory();
        X509Data x509Data = kif.newX509Data(Collections.singletonList(certificate));

        // ...

    } catch (Exception ex) {
        Logger.getLogger(MyClass.class.getName()).log(Level.SEVERE, "Error generating XML Signature", ex);
    }
}

In the code above, a log entry is generated with the private key when an exception occurs. The sensitive information is then stored in the log files, making it accessible to anyone with access to the logs.

For more information, please refer to the following resources

- Apache Santuario Homepage: https://santuario.apache.org/
- CVE-2023-44483 Details: https://nvd.nist.gov/vuln/detail/CVE-2023-44483
- Apache Santuario Security Advisories: https://santuario.apache.org/security-advisories.html

To protect against this vulnerability, users should perform the following actions

1. Upgrade to the latest version of Apache Santuario - XML Security for Java (2.2.6, 2.3.4, or 3..3) as soon as possible.

Disable logging at the debug level, or minimize access to log files.

3. Audit the affected codebase and related dependencies to ensure other vulnerable libraries are not present.
4. Monitor for any unusual server or application activity, indicating attempts to exploit this vulnerability.

By following these recommendations, users can significantly reduce the risk of this vulnerability being exploited and secure their XML processing and signing capabilities.

Timeline

Published on: 10/20/2023 10:15:12 UTC
Last modified on: 10/27/2023 18:49:49 UTC