The validate_as_request function in kdc_util.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrict_anonymous_to_tgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Kerberos_5 | Mit | 1.13 (including) | 1.13 (including) |
| Kerberos_5 | Mit | 1.13.1 (including) | 1.13.1 (including) |
| Kerberos_5 | Mit | 1.13.2 (including) | 1.13.2 (including) |
| Kerberos_5 | Mit | 1.13.3 (including) | 1.13.3 (including) |
| Kerberos_5 | Mit | 1.13.4 (including) | 1.13.4 (including) |
| Kerberos_5 | Mit | 1.13.5 (including) | 1.13.5 (including) |
| Kerberos_5 | Mit | 1.13.6 (including) | 1.13.6 (including) |
| Kerberos_5 | Mit | 1.14 (including) | 1.14 (including) |
| Kerberos_5 | Mit | 1.14.1 (including) | 1.14.1 (including) |
| Kerberos_5 | Mit | 1.14.2 (including) | 1.14.2 (including) |
| Red Hat Enterprise Linux 7 | RedHat | krb5-0:1.14.1-26.el7 | * |
| Krb5 | Ubuntu | precise | * |
| Krb5 | Ubuntu | precise/esm | * |
| Krb5 | Ubuntu | trusty | * |
| Krb5 | Ubuntu | upstream | * |
| Krb5 | Ubuntu | vivid/stable-phone-overlay | * |
| Krb5 | Ubuntu | vivid/ubuntu-core | * |
| Krb5 | Ubuntu | wily | * |
| Krb5 | Ubuntu | xenial | * |