CVE-2024-2698: Freeipa: delegation rules allow a proxy service to impersonate any user to access another target service

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-06-12 · updated 2026-06-17
Weakness: CWE-863

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.

Affected products

FreeIPA ipa: from 4.11.0 before 4.11.2; 4.12.0 — fixed in 4.11.2

How to fix

Upgrade to a fixed version: FreeIPA ipa 4.11.2. Check the vendor advisory for mitigations.

References

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