Summary
Claude Code's Permissive Default Allowlist Enables Unauthorized File Read and Network Exfiltration in Claude Code
Due to an overly broad allowlist of safe commands, it was possible to bypass the Claude Code confirmation prompts to read a file and then send file contents over the network without user confirmation. Reliably exploiting this requires the ability to add untrusted content into a Claude Code context window.
Users on standard Claude Code auto-update received this fix automatically after release. Current users of Claude Code are unaffected, as versions prior to 1.0.24 are deprecated and have been forced to update.
Thank you to https://hackerone.com/wunderwuzzi23 for reporting this issue!
Impact
Untrusted input reaches a shell command, allowing arbitrary commands to run on the host. Typical impact: code execution in the application's environment.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-55284? CVE-2025-55284 is a high-severity OS command injection vulnerability in @anthropic-ai/claude-code (npm), affecting versions < 1.0.4. It is fixed in 1.0.4. Untrusted input reaches a shell command, allowing arbitrary commands to run on the host.
- Which versions of @anthropic-ai/claude-code are affected by CVE-2025-55284? @anthropic-ai/claude-code (npm) versions < 1.0.4 is affected.
- Is there a fix for CVE-2025-55284? Yes. CVE-2025-55284 is fixed in 1.0.4. Upgrade to this version or later.
- Is CVE-2025-55284 exploitable, and should I be worried? Whether CVE-2025-55284 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-55284 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-55284? Upgrade
@anthropic-ai/claude-codeto 1.0.4 or later.