A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function in the LDAP server does not enforce an upper bound on the number of controls per LDAP message. A remote, unauthenticated attacker can send a specially crafted LDAP request containing hundreds of thousands of minimal controls within the default maximum BER message size (2 MB), causing excessive CPU consumption and heap allocation on the server. Under concurrent exploitation, this leads to significant latency degradation, worker thread starvation, or out-of-memory termination, resulting in a denial of service.

A flaw was found in the 389-ds-base server. A heap buffer overflow vulnerability exists in the `schema_attr_enum_callback` function within the `schema.c` file. This occurs because the code incorrectly calculates the buffer size by summing alias string lengths without accounting for additional formatting characters. When a large number of aliases are processed, this oversight can lead to a heap overflow, potentially allowing a remote attacker to cause a Denial of Service (DoS) or achieve Remote Code Execution (RCE).