CVE-2023-7079

Arbitrary remote file read in Wrangler dev server

Workarounds

Configure Wrangler to listen on local interfaces instead with wrangler dev --ip 127.0.0.1. This is the default as of [email protected], and removes the local network as an attack vector, but does not prevent an attack from visiting a malicious website.

References

• https://github.com/cloudflare/workers-sdk/pull/4532
• https://github.com/cloudflare/workers-sdk/pull/4535

Sending specially crafted HTTP requests and inspector messages to Wrangler's dev server could result in any file on the user's computer being accessible over the local network. An attacker that could trick any user on the local network into opening a malicious website could also read any file.

The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.

CVE-2023-7079 has a CVSS score of 6.9 (Medium). The vector is reachable from an adjacent network, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.19.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

This issue was fixed in [email protected]. Wrangler will now only serve files that are part of your bundle, or referenced by your bundle's source maps.

1. What is CVE-2023-7079? CVE-2023-7079 is a medium-severity improper authentication vulnerability in wrangler (npm), affecting versions >= 3.9.0, < 3.19.0. It is fixed in 3.19.0. The application does not adequately verify the identity of a user, device, or process before granting access.
2. How severe is CVE-2023-7079? CVE-2023-7079 has a CVSS score of 6.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of wrangler are affected by CVE-2023-7079? wrangler (npm) versions >= 3.9.0, < 3.19.0 is affected.
4. Is there a fix for CVE-2023-7079? Yes. CVE-2023-7079 is fixed in 3.19.0. Upgrade to this version or later.
5. Is CVE-2023-7079 exploitable, and should I be worried? Whether CVE-2023-7079 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
6. What actually determines whether CVE-2023-7079 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.
7. How do I fix CVE-2023-7079? Upgrade wrangler to 3.19.0 or later.

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