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Lack of Proxy IP headers validation

High
BeryJu published GHSA-cmxp-jcw7-jjjv Jul 6, 2023

Package

authentik

Affected versions

< 2023.5.4
< 2023.4.2

Patched versions

2023.5.5
2023.4.3

Description

Summary

authentik does not verify the source of the X-Forwarded-For and X-Real-IP headers, both in the Python code and the go code.

Impact

Only authentik setups that are directly accessible by users without a reverse proxy are susceptible to this. Possible spoofing of IP addresses in logs, downstream applications proxied by (built in) outpost, IP bypassing in custom flows if used.

Details

This poses a possible security risk when you have flows or policies that check the user's IP address, e.g. when you want to ignore the user's 2 factor authentication when the user is connected to the company network.

Another security risk is that the IP addresses in the logfiles and user sessions is not reliable anymore, anybody can spoof this address and you cannot verify that the user has logged in from the IP address that is in their account's log.

And the third risk is that this header is passed on to the proxied application behind an outpost. The application may do any kind of verification, logging, blocking or rate limiting based on the IP address, and this IP address can be overridden by anybody that want to.

Severity

High

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
Low
Integrity
Low
Availability
Low

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:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L

CVE ID

CVE-2023-36456

Weaknesses

No CWEs

Credits