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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