CVE-2020-9296 Explained : Impact and Mitigation

Netflix Titus is vulnerable to Server-Side Template Injection due to the use of Java Bean Validation custom constraint validators. Attackers can inject arbitrary data in error messages, potentially leading to the execution of arbitrary Java code.

Understanding CVE-2020-9296

Netflix Titus is susceptible to a Server-Side Template Injection vulnerability that could allow attackers to run arbitrary Java code.

What is CVE-2020-9296?

Netflix Titus, utilizing Java Bean Validation custom constraint validators, is exposed to Server-Side Template Injection. This vulnerability enables attackers to execute arbitrary Java code by injecting data into error message templates.

The Impact of CVE-2020-9296

The exploitation of this vulnerability could result in unauthorized execution of Java code within the affected system, potentially leading to further compromise and data breaches.

Technical Details of CVE-2020-9296

Netflix Titus is affected by a Server-Side Template Injection vulnerability that stems from the use of Java Bean Validation custom constraint validators.

Vulnerability Description

The vulnerability arises from the support of different types of interpolation, including Java EL expressions, in error message templates. Attackers can exploit this by injecting arbitrary data into the error message template.

Affected Systems and Versions

Product: Netflix Titus
Vendor: n/a
Versions Affected: All versions prior to v0.1.1-rc.274

Exploitation Mechanism

By injecting malicious data into the error message template passed to ConstraintValidatorContext.buildConstraintViolationWithTemplate() argument, attackers can execute arbitrary Java code.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks posed by CVE-2020-9296.

Immediate Steps to Take

Update Netflix Titus to version v0.1.1-rc.274 or later to eliminate the vulnerability.
Implement strict input validation to prevent unauthorized data injection.

Long-Term Security Practices

Regularly monitor and audit the application for any suspicious activities.
Educate developers on secure coding practices to prevent similar vulnerabilities in the future.

Patching and Updates

Apply security patches and updates promptly to ensure the system is protected against known vulnerabilities.