MIT Kerberos 5 (krb5) through 1.22.2 contains a NULL pointer dereference in make_cred_list() in rd_cred.c that allows authenticated Kerberos clients to crash services by sending mismatched KRB-CRED arrays. Attackers can send forwarded credentials with more tickets than ticket_info entries through gss_accept_sec_context() to crash GSS-API acceptor services, causing denial of service.
Weakness
The product dereferences a pointer that it expects to be valid but is NULL.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat Hardened Images | RedHat | krb5-main-1.22.2-10.3.hum1 | * |
Potential Mitigations
References
- https://github.com/krb5/krb5
- https://github.com/krb5/krb5/blob/krb5-1.22.2-final/src/lib/krb5/krb/rd_cred.c#L77-L112
- https://github.com/krb5/krb5/commit/48afa9abb89ab2176bb20624d87d010b9984fc08
- https://github.com/krb5/krb5/commit/62196e2b269159a5465f5b8d0ed7cf6f29c3282a
- https://github.com/krb5/krb5/pull/1511
- https://www.vulncheck.com/advisories/mit-krb5-through-1.22.2-null-pointer-dereference-via-krb5-rd-cred