Описание
Handlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and Options
Summary
The Handlebars CLI precompiler (bin/handlebars / lib/precompiler.js) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser.
Description
lib/precompiler.js generates JavaScript source by string-interpolating several values directly into the output. Four distinct injection points exist:
1. Template name injection
template.name is derived from the file system path. A filename containing " or ']; breaks out of the string literal and injects arbitrary JavaScript.
2. Namespace injection (-n / --namespace)
opts.namespace is emitted as raw JavaScript. Anything after a ; in the value becomes an additional JavaScript statement.
3. CommonJS path injection (-c / --commonjs)
opts.commonjs is interpolated inside double quotes with no escaping, allowing " to close the string and inject further code.
4. AMD path injection (-h / --handlebarPath)
opts.handlebarPath is interpolated inside single quotes, allowing ' to close the array element.
All four injection points result in code that executes when the generated bundle is require()d or loaded in a browser.
Proof of Concept
Template name vector (creates a file pwned on disk):
Namespace vector:
CommonJS vector:
AMD vector:
Workarounds
- Validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (
",',;, etc.). - Use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines.
- Run the precompiler in a sandboxed environment (container with no write access to sensitive paths) to limit the impact of successful exploitation.
- Audit template filenames in any repository or package that is consumed by an automated build pipeline.
Ссылки
Пакеты
handlebars
>= 4.0.0, <= 4.7.8
4.7.9
Связанные уязвимости
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (`"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write ac...
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (`"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write a...
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values that contain characters with JavaScript string-escaping significance (`"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write acce
Handlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and Options
Handlebars provides the power necessary to let users build semantic te ...