""ET EXPLOIT Exim Stack Exhaustion via BDAT Error Inbound (CVE-2020-28019)""

SID: 2032903

Revision: 2

Class Type: attempted-admin

Metadata: attack_target SMTP_Server, created_at 2021_05_04, cve CVE_2020_28019, deployment Perimeter, deployment Internal, signature_severity Major, updated_at 2021_05_04

Reference:

  • cve

  • 2020-28019

Protocol: tcp

Source Network: any

Source Port: any

Destination Network: [$HOME_NET,$HTTP_SERVERS,$SMTP_SERVERS]

Destination Port: [25,26,587]

Flow: established,to_server

Contents:

  • Value: "BDAT|20|"

  • Value: "BDAT|20|"

Within:

PCRE: "/^[^\r\n]{50,}/R"

Special Options:

  • fast_pattern

source