lib/kadm5/kadm_rpc_xdr.c in MIT Kerberos 5 (aka krb5) before 1.20.2 and 1.21.x before 1.21.1 frees an uninitialized pointer. A remote authenticated user can trigger a kadmind crash. This occurs because _xdr_kadm5_principal_ent_rec does not validate the relationship between n_key_data and the key_data array count.
The product accesses or uses a pointer that has not been initialized.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Kerberos_5 | Mit | * | 1.20.2 (excluding) |
| Kerberos_5 | Mit | 1.21 (including) | 1.21 (including) |
| Kerberos_5 | Mit | 1.21-beta1 (including) | 1.21-beta1 (including) |
| Red Hat Enterprise Linux 9 | RedHat | krb5-0:1.21.1-1.el9 | * |
| Red Hat Enterprise Linux 9 | RedHat | krb5-0:1.21.1-1.el9 | * |
| Krb5 | Ubuntu | bionic | * |
| Krb5 | Ubuntu | esm-apps/bionic | * |
| Krb5 | Ubuntu | esm-infra/bionic | * |
| Krb5 | Ubuntu | esm-infra/xenial | * |
| Krb5 | Ubuntu | focal | * |
| Krb5 | Ubuntu | jammy | * |
| Krb5 | Ubuntu | lunar | * |
| Krb5 | Ubuntu | trusty | * |
| Krb5 | Ubuntu | trusty/esm | * |
| Krb5 | Ubuntu | upstream | * |
| Krb5 | Ubuntu | xenial | * |
If the pointer contains an uninitialized value, then the value might not point to a valid memory location. This could cause the product to read from or write to unexpected memory locations, leading to a denial of service. If the uninitialized pointer is used as a function call, then arbitrary functions could be invoked. If an attacker can influence the portion of uninitialized memory that is contained in the pointer, this weakness could be leveraged to execute code or perform other attacks. Depending on memory layout, associated memory management behaviors, and product operation, the attacker might be able to influence the contents of the uninitialized pointer, thus gaining more fine-grained control of the memory location to be accessed.