An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. The reference count is maintained as an int; on LP64 systems this can cause the reference count to overflow if the client creates a large number of wlshm buffer objects, or if it can coerce the server to create a large number of external references to the buffer storage. With the reference count overflowing, a use-after-free can be constructed on the wlshmpool tracking structure, where values may be incremented or decremented; it may also be possible to construct a limited oracle to leak 4 bytes of server-side memory to the attacking client at a time.

eM Client before 7.2.33412.0 automatically imported S/MIME certificates and thereby silently replaced existing ones. This allowed a man-in-the-middle attacker to obtain an email-validated S/MIME certificate from a trusted CA and replace the public key of the entity to be impersonated. This enabled the attacker to decipher further communication. The entire attack could be accomplished by sending a single email.