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GHSA-f8mp-x433-5wpf
No affected components available
Impact
The V8 inspector intentionally allows arbitrary code execution within the Workers sandbox for debugging. wrangler dev would previously start an inspector server listening on all network interfaces. This would allow an attacker on the local network to connect to the inspector and run arbitrary code. Additionally, the inspector server did not validate Origin/Host headers, granting an attacker that can trick any user on the local network into opening a malicious website the ability to run code. If wrangler dev --remote was being used, an attacker could access production resources if they were bound to the worker.
Patches
This issue was fixed in wrangler@3.19.0 and wrangler@2.20.2. Whilst wrangler dev's inspector server listens on local interfaces by default as of wrangler@3.16.0, an SSRF vulnerability in miniflare allowed access from the local network until wrangler@3.18.0. wrangler@3.19.0 and wrangler@2.20.2 introduced validation for the Origin/Host headers.
Workarounds
Unfortunately, Wrangler doesn't provide any configuration for which host that inspector server should listen on. Please upgrade to at least wrangler@3.16.0, and configure Wrangler to listen on local interfaces instead with wrangler dev --ip 127.0.0.1 to prevent SSRF. This 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/issues/4430
- https://github.com/cloudflare/workers-sdk/pull/4437
- https://github.com/cloudflare/workers-sdk/pull/4535
- https://github.com/cloudflare/workers-sdk/pull/4550
The vulnerability can be exploited over a local network, such as Wi-Fi. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data.
Exploitation activity has been observed. Apply available patches or mitigations urgently.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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