CVE-2025-23026 in jte
Summary
by MITRE • 01/13/2025
jte (Java Template Engine) is a secure and lightweight template engine for Java and Kotlin. In affected versions Jte HTML templates with `script` tags or script attributes that include a Javascript template string (backticks) are subject to XSS. The `javaScriptBlock` and `javaScriptAttribute` methods in the `Escape` class do not escape backticks, which are used for Javascript template strings. Dollar signs in template strings should also be escaped as well to prevent undesired interpolation. HTML templates rendered by Jte's `OwaspHtmlTemplateOutput` in versions less than or equal to `3.1.15` with `script` tags or script attributes that contain Javascript template strings (backticks) are vulnerable. Users are advised to upgrade to version 3.1.16 or later to resolve this issue. There are no known workarounds for this vulnerability.
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Analysis
by VulDB Data Team • 02/13/2025
The vulnerability identified as CVE-2025-23026 affects the jte Java Template Engine, a lightweight and secure template engine designed for Java and Kotlin applications. This security flaw manifests in versions up to and including 3.1.15 where HTML templates containing script tags or script attributes with JavaScript template strings are susceptible to cross-site scripting attacks. The vulnerability specifically targets the Escape class methods javaScriptBlock and javaScriptAttribute which fail to properly escape backticks character used in JavaScript template literals. According to CWE-79, this represents a classic cross-site scripting vulnerability where untrusted data is embedded into web pages without proper sanitization, creating opportunities for malicious script execution in the context of the victim's browser.
The technical implementation flaw occurs within the OWASP HTML template output processing mechanism of jte where the Escape class does not adequately handle JavaScript template strings that utilize backtick characters for string interpolation. JavaScript template strings defined by backticks allow for embedded expressions using ${} syntax which can trigger unintended variable interpolation when these strings are rendered in HTML contexts. The vulnerability extends beyond just backticks to include dollar signs within template strings that should also be escaped to prevent undesired interpolation behavior. This issue is particularly dangerous because it allows attackers to inject malicious JavaScript code that executes in the victim's browser context, potentially leading to session hijacking, data theft, or other malicious activities. The vulnerability aligns with ATT&CK technique T1566.001 which involves the exploitation of web application vulnerabilities through cross-site scripting attacks.
The operational impact of this vulnerability is significant for applications using jte template engine, particularly those that render user-supplied content within script tags or script attributes. When templates containing JavaScript template strings are processed through the vulnerable OwaspHtmlTemplateOutput, attackers can inject malicious code that executes in the victim's browser, potentially compromising user sessions and data confidentiality. The vulnerability affects both script tags and script attributes, broadening the attack surface and making it more challenging to mitigate. Organizations utilizing jte versions 3.1.15 or earlier face potential exposure to various attack vectors including credential theft, session manipulation, and data exfiltration. The lack of known workarounds means that organizations cannot implement temporary fixes while awaiting the official patch, making immediate upgrade to version 3.1.16 or later essential for maintaining security posture.
Mitigation of CVE-2025-23026 requires immediate upgrade to jte version 3.1.16 or later where the escape functions properly handle backticks and dollar signs in JavaScript template strings. Security teams should conduct comprehensive vulnerability assessments across all applications utilizing jte to identify potentially affected templates and code paths. Organizations should implement automated monitoring for vulnerable jte versions in their software supply chains and establish processes for rapid patch deployment. Additionally, security teams should review their template rendering logic to ensure proper input sanitization and consider implementing additional security controls such as content security policies to limit the impact of potential exploitation. The fix addresses the underlying CWE-79 vulnerability by ensuring proper HTML escaping of template string delimiters and prevents the unintended interpolation of user-supplied data in JavaScript contexts.