los investigadores descubrieron Qualys una vulnerabilidad crítica que afecta a más de la mitad de los servidores de correo.
The problem was detected in the Exim Mail Transfer Agent (MTA) software, que se instala en los servidores de correo para la entrega de mensajes de correo electrónico del remitente al destinatario.De acuerdo con datos de junio 2019, Exim se fija en 57% (507,389) de todos los servidores que se encuentran en Internet. sin embargo, there is information that in fact the number of Exim installations exceeds this number tenfold and is estimated as 5.4 millón.
Detected by Qualys experts vulnerabilities affect software versions desde 4.87 a 4.91. La vulnerabilidad permite a un atacante remoto / local para lanzar comandos en el servidor de correo con privilegios de superusuario.
leer también: Mas que 50,000 servidores MS-SQL y phpMyAdmin fueron infectados por rootkits y mineros
Local attacker, even with the lowest privileges, can exploit it immediately. sin embargo, the most dangerous are remote attackers who scan the Internet for vulnerable servers and are able to take control of vulnerable systems.
For remote exploitation of the default configuration, an attacker must maintain a connection to the vulnerable server for seven days (by sending one byte every few minutes).
“For transmitting one by one for each day (by transmitting one byte every few minutes). sin embargo, we cannot guarantee that this method of exploitation is unique; faster methods may exist”, – admit researchers.
Adicionalmente, they indicate that vulnerability can be exploited remotely not only with the default configuration settings.
The problem was fixed in the version of Exim 4.92, released in February of this year. It is noteworthy that at the time of new software’s version release, vulnerability was not yet known, and it was fixed accidentally. Researchers discovered the problem only during the audit of old Exim versions.
Vulnerability assigned an identifier CVE-desde 2.019 hasta 10.149, in Qualys, it passes under the name “El retorno del asistente“.
Fuente: https://www.openwall.com
