CyberSecBulletin
CVE-2022-24778NVD status: Modified

imgcrypt: Incorrect Authorization

Published Updated By the CyberSecBulletin desk

CVE-2022-24778 is a high-severity incorrect authorization vulnerability in imgcrypt from Containerd, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected imgcrypt versions: < 1.1.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.72% chance of exploitation within 30 days, higher than 86% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of imgcrypt 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.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Containerdimgcrypt< 1.1.4Not stated
Fedora ProjectFedora34; 35; 36Not 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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (github.com)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

The imgcrypt library provides API exensions for containerd to support encrypted container images and implements the ctd-decoder command line tool for use by containerd to decrypt encrypted container images. The imgcrypt function `CheckAuthorization` is supposed to check whether the current used is authorized to access an encrypted image and prevent the user from running an image that another user previously decrypted on the same system. In versions prior to 1.1.4, a failure occurs when an image with a ManifestList is used and the architecture of the local host is not the first one in the ManifestList. Only the first architecture in the list was tested, which may not have its layers available locally since it could not be run on the host architecture. Therefore, the verdict on unavailable layers was that the image could be run anticipating that image run failure would occur later due to the layers not being available. However, this verdict to allow the image to run enabled other architectures in the ManifestList to run an image without providing keys if that image had previously been decrypted. A patch has been applied to imgcrypt 1.1.4. Workarounds may include usage of different namespaces for each remote user.

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

The underlying weakness: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Incorrect Authorization vulnerabilities (CWE-863)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Recent Incorrect Authorization vulnerabilities

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