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).
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().