Exim < 4.89.1 Use-After-Free BDAT Remote Code Execution
Critical Nessus Plugin ID 104815
SynopsisThe remote mail server is potentially affected by a remote code execution flaw.
DescriptionAccording to its banner and supported extensions, the remote installation of Exim is affected by a code execution flaw. The implementation of the BDAT SMTP verb for sending large binary messages introduced in Exim 4.88 can incorrectly free an in-use region of memory, leading to memory corruption and potentially allowing an attacker to execute code.
SolutionUpdate to Exim 4.89.1 or later, or Exim 4.90-RC3 or later. If you cannot upgrade, edit your Exim configuration and set 'chunking_advertise_hosts' to an empty value as a workaround.