Apache James prior to release 3.6.3 and 3.7.1 is vulnerable to a buffering attack relying on the use of the STARTTLS command. Fix of CVE-2021-38542, which solved similar problem fron Apache James 3.6.1, is subject to a parser differential and do not take into account concurrent requests.

Apache James prior to release 3.6.1 is vulnerable to a buffering attack relying on the use of the STARTTLS command. This can result in Man-in -the-middle command injection attacks, leading potentially to leakage of sensible information.