Uninitialized Memory Exposure Affecting tunnel-agent package, versions <0.6.0
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Test your applications- Snyk ID npm:tunnel-agent:20170305
- published 5 Jul 2017
- disclosed 4 Mar 2017
- credit ChALkeR
How to fix?
Upgrade tunnel-agent
to version 0.6.0 or higher.
Note This is vulnerable only for Node <=4
Overview
tunnel-agent
is HTTP proxy tunneling agent. Affected versions of the package are vulnerable to Uninitialized Memory Exposure.
A possible memory disclosure vulnerability exists when a value of type number
is used to set the proxy.auth option of a request request
and results in a possible uninitialized memory exposures in the request body.
This is a result of unobstructed use of the Buffer
constructor, whose insecure default constructor increases the odds of memory leakage.
Details
Constructing a Buffer
class with integer N
creates a Buffer
of length N
with raw (not "zero-ed") memory.
In the following example, the first call would allocate 100 bytes of memory, while the second example will allocate the memory needed for the string "100":
// uninitialized Buffer of length 100
x = new Buffer(100);
// initialized Buffer with value of '100'
x = new Buffer('100');
tunnel-agent
's request
construction uses the default Buffer
constructor as-is, making it easy to append uninitialized memory to an existing list. If the value of the buffer list is exposed to users, it may expose raw server side memory, potentially holding secrets, private data and code. This is a similar vulnerability to the infamous Heartbleed
flaw in OpenSSL.
Proof of concept by ChALkeR
require('request')({
method: 'GET',
uri: 'http://www.example.com',
tunnel: true,
proxy:{
protocol: 'http:',
host:"127.0.0.1",
port:8080,
auth:80
}
});
You can read more about the insecure Buffer
behavior on our blog.
Similar vulnerabilities were discovered in request, mongoose, ws and sequelize.