CVE-2016-10518: Buffer Overflow
A vulnerability was found in the ping functionality of the ws module before 1.0.0 which allowed clients to allocate memory by sending a ping frame. The ping functionality by default responds with a pong frame and the previously given payload of the ping frame. This is exactly what you expect, but internally ws always transforms all data that we need to send to a Buffer instance and that is where the vulnerability existed. ws didn't do any checks for the type of data it was sending. With buffers in node when you allocate it when a number instead of a string it will allocate the amount of bytes.
Other sources
Versions of ws prior to 1.0.1 are affected by a remote memory disclosure vulnerability.
In certain rare circumstances, applications which allow users to control the arguments of a client.ping() call will cause ws to send the contents of an allocated but non-zero-filled buffer to the server. This may disclose sensitive information that still exists in memory after previous use of the memory for other tasks.
Proof of Concept var ws = require('ws')
var server = new ws.Server({ port: 9000 }) var client = new ws('ws://localhost:9000')
client.on('open', function () { console.log('open') client.ping(50) // this sends a non-zeroed buffer of 50 bytes
client.on('pong', function (data) { console.log('got pong') console.log(data) // Data from the client. }) })
Recommendation
Update to version 1.0.1 or greater.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2016-10518?
CVE-2016-10518 is a remote memory disclosure vulnerability in the ping functionality of the ws module before version 1.0.1.
How does CVE-2016-10518 affect applications using the ws module?
Applications using the ws module versions prior to 1.0.1 are affected by CVE-2016-10518, which can result in the disclosure of memory contents.
How can users control the arguments of a client.ping() call to trigger CVE-2016-10518?
Certain rare circumstances allow users to control the arguments of a client.ping() call, triggering the vulnerability in the ws module before version 1.0.1.
What is the severity of CVE-2016-10518?
CVE-2016-10518 has a severity rating of 7.5 (high).
How can I fix CVE-2016-10518 vulnerability in the ws module?
To fix the CVE-2016-10518 vulnerability, update the ws module to version 1.0.1 or newer.