CyberSecBulletin
CVE-2022-46179NVD status: Modified

LiuOS: Authorization Bypass Through User-Controlled Key

Published Updated By the CyberSecBulletin desk

CVE-2022-46179 is a high-severity authorization bypass through user-controlled key vulnerability in LiuOS from LiuWoodsCode, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected LiuOS versions: <= 0.1.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of LiuOS you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
LiuWoodsCodeLiuOS<= 0.1.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.2CriticalCNA (github.com)
CVSS 3.17.8HighNVD

Official description

LiuOS is a small Python project meant to imitate the functions of a regular operating system. Version 0.1.0 and prior of LiuOS allow an attacker to set the GITHUB_ACTIONS environment variable to anything other than null or true and skip authentication checks. This issue is patched in the latest commit (c658b4f3e57258acf5f6207a90c2f2169698ae22) by requiring the var to be set to true, causing a test script to run instead of being able to login. A potential workaround is to check for the GITHUB_ACTIONS environment variable and set it to "" (no quotes) to null the variable and force credential checks.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

How developers prevent this class of flaw

  • For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
  • Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
  • Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.

More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Authorization Bypass Through User-Controlled Key vulnerabilities

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