Skip to content

SSRF via X-Skipper-Proxy

Critical
szuecs published GHSA-f2rj-m42r-6jm2 Oct 24, 2022

Package

gomod github.com/zalando/skipper (Go)

Affected versions

< v0.13.237

Patched versions

v0.13.237

Description

Impact

Skipper prior to version v0.13.236 is vulnerable to server-side request forgery (SSRF). An attacker can exploit a vulnerable version of proxy to access the internal metadata server or other unauthenticated URLs by adding an specific header (X-Skipper-Proxy) to the http request.

Patches

The problem was patched in version https://github.com/zalando/skipper/releases/tag/v0.13.237.
Users need to upgrade to skipper >=v0.13.237.

Workarounds

Use dropRequestHeader("X-Skipper-Proxy") filter

References

https://github.com/zalando/skipper/releases/tag/v0.13.237

For more information

If you have any questions or comments about this advisory:

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N

CVE ID

CVE-2022-38580

Weaknesses

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Learn more on MITRE.