All versions of Node.js 9.x and 10.x are vulnerable and the severity is HIGH. An attacker can cause a denial of service (DoS) by causing a node process which provides an http server supporting TLS server to crash. This can be accomplished by sending duplicate/unexpected messages during the handshake. This vulnerability has been addressed by updating the TLS implementation.
Node.js versions 9.7.0 and later and 10.x are vulnerable and the severity is MEDIUM. A bug introduced in 9.7.0 increases the memory consumed when reading from the network into JavaScript using the net.Socket object directly as a stream. An attacker could use this cause a denial of service by sending tiny chunks of data in short succession. This vulnerability was restored by reverting to the prior behaviour.
Calling Buffer.fill() or Buffer.alloc() with some parameters can lead to a hang which could result in a Denial of Service. In order to address this vulnerability, the implementations of Buffer.alloc() and Buffer.fill() were updated so that they zero fill instead of hanging in these cases. All versions of Node.js 6.x (LTS "Boron"), 8.x (LTS "Carbon"), and 9.x are vulnerable. All versions of Node.js 10.x (Current) are NOT vulnerable.
During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2-1.0.2o).
The sync-exec module is used to simulate child_process.execSync in node versions <0.11.9. Sync-exec uses tmp directories as a buffer before returning values. Other users on the server have read access to the tmp directory, possibly allowing an attacker on the server to obtain confidential information from the buffer/tmp file, while it exists.
The `'path'` module in the Node.js 4.x release line contains a potential regular expression denial of service (ReDoS) vector. The code in question was replaced in Node.js 6.x and later so this vulnerability only impacts all versions of Node.js 4.x. The regular expression, `splitPathRe`, used within the `'path'` module for the various path parsing functions, including `path.dirname()`, `path.extname()` and `path.parse()` was structured in such a way as to allow an attacker to craft a string, that when passed through one of these functions, could take a significant amount of time to evaluate, potentially leading to a full denial of service.
The HTTP parser in all current versions of Node.js ignores spaces in the `Content-Length` header, allowing input such as `Content-Length: 1 2` to be interpreted as having a value of `12`. The HTTP specification does not allow for spaces in the `Content-Length` value and the Node.js HTTP parser has been brought into line on this particular difference. The security risk of this flaw to Node.js users is considered to be VERY LOW as it is difficult, and may be impossible, to craft an attack that makes use of this flaw in a way that could not already be achieved by supplying an incorrect value for `Content-Length`. Vulnerabilities may exist in user-code that make incorrect assumptions about the potential accuracy of this value compared to the actual length of the data supplied. Node.js users crafting lower-level HTTP utilities are advised to re-check the length of any input supplied after parsing is complete.
The Node.js inspector, in 6.x and later is vulnerable to a DNS rebinding attack which could be exploited to perform remote code execution. An attack is possible from malicious websites open in a web browser on the same computer, or another computer with network access to the computer running the Node.js process. A malicious website could use a DNS rebinding attack to trick the web browser to bypass same-origin-policy checks and to allow HTTP connections to localhost or to hosts on the local network. If a Node.js process with the debug port active is running on localhost or on a host on the local network, the malicious website could connect to it as a debugger, and get full code execution access.
nghttp2 version >= 1.10.0 and nghttp2 <= v1.31.0 contains an Improper Input Validation CWE-20 vulnerability in ALTSVC frame handling that can result in segmentation fault leading to denial of service. This attack appears to be exploitable via network client. This vulnerability appears to have been fixed in >= 1.31.1.
Node.js was affected by OpenSSL vulnerability CVE-2017-3737 in regards to the use of SSL_read() due to TLS handshake failure. The result was that an active network attacker could send application data to Node.js using the TLS or HTTP2 modules in a way that bypassed TLS authentication and encryption.