Visual Element Onslaught
- Javier Conejo del Cerro
- hace 3 días
- 2 Min. de lectura
In May 2025, a critical remote code execution (RCE) vulnerability shook the AWS Amplify Studio ecosystem. Tracked as CVE-2025-4318 and rated 9.5 on the CVSS scale, the flaw resided in the @aws-amplify/codegen-ui package—a core dependency responsible for generating React code from visual UI components. The root cause? Unsafe evaluation of user-supplied JavaScript expressions within component schemas, processed through insecure methods like eval() and new Function().
This vulnerability turned visual elements into dangerous attack vectors. By embedding malicious JavaScript in seemingly harmless UI configurations, attackers could achieve full code execution on backend systems—directly from the JSON schemas intended to streamline front-end development.
Developers and Backend Systems, Quickly Targeted
The primary victims were developers and product teams leveraging Amplify Studio to build interfaces using low-code tools. Often working in fast-paced environments with automated CI/CD pipelines, these teams enjoyed the efficiency and convenience of visually designing components and exporting them as code.
However, this same flexibility became their Achilles’ heel. Many users had editing privileges and worked in shared environments, meaning a single malicious schema—once introduced—could compromise an entire build system. The incident underlines how low-code platforms can unintentionally widen the attack surface, especially when they allow for the execution of arbitrary expressions without proper restrictions.
AWS Tokens, Taken
The attack chain began with the injection of malicious JavaScript into a component schema. This could be as simple as adding a malicious value to a placeholder field:
{
"componentType": "TextField",
"name": "MaliciousRCEComponent",
"properties": {
"label": { "value": "Exploitable Field" },
"placeholder": { "value": "require('child_process').execSync('touch /tmp/rce-success')" }
}
}
When the vulnerable version of Amplify’s code generation tool parsed this schema, the unsafe evaluation logic would execute the shell command, allowing attackers to:
Steal AWS credentials from the build environment.
Access sensitive source code or configuration files.
Interrupt CI/CD pipelines or spread to downstream dependencies.
Persist silently within the developer workflow.
The threat was particularly acute in organizations with shared build infrastructure, where one compromised component could lead to widespread impact.
Audit, Restrict and Avoid
AWS released a patched version, v2.20.3, that replaces the unsafe logic with a safeEval() function, applying strict input filtering and keyword blacklisting. But patching is just one layer of defense.
To truly secure development environments, organizations must:
Immediately upgrade to @aws-amplify/codegen-ui v2.20.3 or later.
Audit all UI component schemas for injected or suspicious expressions.
Restrict editing privileges to trusted developers only.
Avoid dynamic code evaluation in any user-controlled context.
Ensure custom forks or derivations also apply the patch.
Use static analysis and sandboxing to reduce risk at the pipeline level.
This vulnerability serves as a stark reminder: when front-end tools evaluate untrusted input, the line between design and compromise blurs. Even the most convenient developer features can become high-impact attack surfaces when security principles like input validation, privilege control, and code isolation are not enforced.
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