Callback-url-file-3a-2f-2f-2fhome-2f-2a-2f.aws-2fcredentials -

Long-term (1–3 months)

The string you provided, callback-url-file-3A-2F-2F-2Fhome-2F-2A-2F.aws-2Fcredentials , appears to be a URL-encoded path designed to target sensitive local files, specifically the located at file:///home/*/.aws/credentials . callback-url-file-3A-2F-2F-2Fhome-2F-2A-2F.aws-2Fcredentials

Local File URI Callback for Credential Delivery I’ve been looking into how common "callback URL"

: By URL-encoding the path to the AWS credentials file ( file:///home/*/.aws/credentials ), an attacker could trick a vulnerable service into reading the local file and sending its contents to an attacker-controlled server as part of a "callback" mechanism. callback-url-file-3A-2F-2F-2Fhome-2F-2A-2F.aws-2Fcredentials

By providing this string to a parameter that expects a URL (like a webhook or profile picture uploader), an attacker attempts to force the server to "fetch" its own local secret files and return the contents in the application response.

I’ve been looking into how common "callback URL" parameters can be weaponized to exfiltrate sensitive cloud metadata. A common payload I'm seeing in logs looks like this: ?callbackUrl=file:///home/*/.aws/credentials 🔍 What is happening? Attackers use the