CVE-2024-2698

Description

A vulnerability was found in FreeIPA in how the initial implementation of MS-SFU by MIT Kerberos was missing a condition for granting the "forwardable" flag on S4U2Self tickets. Fixing this mistake required adding a special case for the check_allowed_to_delegate() function: If the target service argument is NULL, then it means the KDC is probing for general constrained delegation rules and not checking a specific S4U2Proxy request.

In FreeIPA 4.11.0, the behavior of ipadb_match_acl() was modified to match the changes from upstream MIT Kerberos 1.20. However, a mistake resulting in this mechanism applies in cases where the target service argument is set AND where it is unset. This results in S4U2Proxy requests being accepted regardless of whether or not there is a matching service delegation rule.

Statement

This vulnerability does not affect default FreeIPA deployments because the services that have delegation rules defined are on IPA servers themselves. Services having resource-based constrained delegation (RBCD) rules are not affected by this vulnerability.

Mitigation

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score8.88.8N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredLowLowN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityHighHighN/A
Integrity ImpactHighHighN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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

Understanding the Weakness (CWE)

Confidentiality

Technical Impact: Read Application Data; Read Files or Directories

An attacker could bypass intended access restrictions to read sensitive data, either by reading the data directly from a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to read the data.

Integrity

Technical Impact: Modify Application Data; Modify Files or Directories

An attacker could bypass intended access restrictions to modify sensitive data, either by writing the data directly to a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to write the data.

Access Control

Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism

An attacker could bypass intended access restrictions to gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.

Confidentiality,Integrity,Availability

Technical Impact: Execute Unauthorized Code or Commands

An attacker could use elevated privileges to execute unauthorized commands or code.

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)

An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.

Frequently Asked Questions

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