In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)
An issue was discovered in Pure-FTPd 1.0.49. An uninitialized pointer vulnerability has been detected in the diraliases linked list. When the *lookup_alias(const char alias) or print_aliases(void) function is called, they fail to correctly detect the end of the linked list and try to access a non-existent list member. This is related to init_aliases in diraliases.c.