CVE-2024-2698 – This vulnerability in FreeIPA allows attackers ... (How to Fix)

Q: What is the severity of CVE-2024-2698?

CVE-2024-2698 has a CVSS score of 8.8 (HIGH). This vulnerability in FreeIPA allows attackers to bypass constrained delegation rules in Kerberos S4U2Proxy requests, enabling unauthorized service impersonation. It affects FreeIPA deployments using MIT Kerberos with MS-SFU extensions. Attackers could impersonate services they shouldn't have access to.

📋 TL;DR

This vulnerability in FreeIPA allows attackers to bypass constrained delegation rules in Kerberos S4U2Proxy requests, enabling unauthorized service impersonation. It affects FreeIPA deployments using MIT Kerberos with MS-SFU extensions. Attackers could impersonate services they shouldn't have access to.

💻 Affected Systems

Products:

FreeIPA

Versions: FreeIPA 4.11.0 and later versions before patches

Operating Systems: RHEL, CentOS, Fedora, and other Linux distributions running FreeIPA

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects deployments using constrained delegation with MS-SFU extensions; requires Kerberos authentication infrastructure.

📦 What is this software?

Freeipa by Freeipa

View all CVEs affecting Freeipa →

Freeipa by Freeipa

View all CVEs affecting Freeipa →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete compromise of Kerberos authentication system allowing attackers to impersonate any service, potentially leading to domain-wide privilege escalation and data exfiltration.

🟠

Likely Case

Unauthorized access to specific services through delegation bypass, potentially compromising sensitive data or performing lateral movement.

🟢

If Mitigated

Limited impact if proper network segmentation and service isolation are in place, though authentication bypass remains possible.

🌐 Internet-Facing: MEDIUM - FreeIPA servers are typically internal but may be exposed in hybrid environments; exploitation requires Kerberos access.

🏢 Internal Only: HIGH - Most FreeIPA deployments are internal; successful exploitation could compromise entire authentication infrastructure.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires understanding of Kerberos delegation mechanisms and access to Kerberos infrastructure; no public exploits known as of analysis.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check specific Red Hat advisories for patched versions (RHSA-2024:3754, RHSA-2024:3755, etc.)

Vendor Advisory: https://access.redhat.com/security/cve/CVE-2024-2698

Restart Required: Yes

Instructions:

1. Apply Red Hat security updates via 'yum update freeipa-server' 2. Restart FreeIPA services 3. Verify patch application with version check

🔧 Temporary Workarounds

Disable constrained delegation

linux

Temporarily disable constrained delegation features if not required

# Modify FreeIPA configuration to restrict delegation rules
# Specific commands depend on deployment configuration

🧯 If You Can't Patch

Implement strict network segmentation around FreeIPA servers
Enhance monitoring for unusual delegation requests in Kerberos logs

🔍 How to Verify

Check if Vulnerable:

Check FreeIPA version with 'ipa --version' and compare against affected versions (4.11.0+ before patches)

Check Version:

ipa --version && rpm -q freeipa-server

Verify Fix Applied:

Verify updated package version with 'rpm -q freeipa-server' and check for advisory patches

📡 Detection & Monitoring

Log Indicators:

Unusual S4U2Proxy requests in Kerberos KDC logs
Delegation requests without matching service rules
Failed delegation checks followed by successful authentication

Network Indicators:

Unexpected Kerberos service ticket requests
Anomalous cross-service authentication patterns

SIEM Query:

source="kerberos.log" AND ("S4U2Proxy" OR "delegation") AND NOT "allowed_delegation"

📊 Metadata

CVE ID: CVE-2024-2698

CVSS v3 Score: 8.8 (HIGH)

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

CWE: CWE-863

Published: June 12, 2024

Last Updated: November 24, 2024

🔗 References

https://access.redhat.com/errata/RHSA-2024:3754 Vendor Advisory
https://access.redhat.com/errata/RHSA-2024:3755 Vendor Advisory
https://access.redhat.com/errata/RHSA-2024:3757 Vendor Advisory
https://access.redhat.com/errata/RHSA-2024:3759 Vendor Advisory
https://access.redhat.com/security/cve/CVE-2024-2698 Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2270353 Issue Tracking,Mitigation,Vendor Advisory
https://www.freeipa.org/release-notes/4-12-1.html Release Notes
https://access.redhat.com/errata/RHSA-2024:3754 Vendor Advisory
https://access.redhat.com/errata/RHSA-2024:3755 Vendor Advisory
https://access.redhat.com/errata/RHSA-2024:3757 Vendor Advisory
https://access.redhat.com/errata/RHSA-2024:3759 Vendor Advisory
https://access.redhat.com/security/cve/CVE-2024-2698 Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2270353 Issue Tracking,Mitigation,Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WT3JL7JQDIAFKKEFARWYES7GZNWGQNCI/
https://www.freeipa.org/release-notes/4-12-1.html Release Notes

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