Portkey.ai Gateway: Server-Side Request Forgery (SSRF) in Custom Host

CVE-2025-66405 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Summary

The gateway determines the destination baseURL by prioritizing the value in the x-portkey-custom-host request header. The proxy route then appends the client-specified path to perform an external fetch. This can be maliciously used by users for SSRF (CWE-918) attack

Impact

This vulnerability can be exploited to force the server to make requests to arbitrary hosts on the internal network. This could allow an attacker to exfiltrate sensitive data, for instance, by accessing the AWS metadata service.

Patches

The issue is patched in 1.14.0 (https://github.com/Portkey-AI/gateway/pull/1372)

The vulnerability resides within the gateway's request processing function which handles the x-portkey-custom-host header. This parameter was passed directly or with insufficient validation/sanitization to an internal HTTP request function.

The fix (v1.14.0) implements a robust allow-list policy:

  1. All custom host inputs are now strictly validated to ensure the resulting URI points only to trusted, expected external services.

  2. The implementation now explicitly blocks requests to non-routable IP addresses, loopback addresses, private networks and standard metadata endpoints.

Credit

This vulnerability was discovered and reported responsibly by @im-soohyun. We thank them for their adherence to coordinated vulnerability disclosure principles.

References

https://cwe.mitre.org/data/definitions/918.html

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2025-12-02 01:08:37 UTC
Updated
2025-12-02 01:08:38 UTC
GitHub reviewed
2025-12-02 01:08:37 UTC
NVD published
2025-12-01 23:15:53 UTC

EPSS Score

Score Percentile
0.07% 22.49%

CVSS Scores

Base score Version Severity Vector
6.9 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:L)
Limited confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:L)
Limited integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.

Identifiers

Type Value
GHSA GHSA-hhh5-2cvx-vmfp ↗
CVE CVE-2025-66405 ↗

CWEs

CWE id Name
CWE-918 Server-Side Request Forgery (SSRF)

Credits

  • im-soohyun (finder)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm @portkey-ai/gateway < 1.14.0 1.14.0 —

References

cvelogic Threat Intelligence