Executive brief
Sendmail is a widely used mail transfer agent responsible for routing and delivering email across the internet. A critical vulnerability allows remote attackers to take complete control of the mail server by sending specially crafted email messages. This could lead to the theft of sensitive communications, total service disruption, or the use of the server as a staging ground for further attacks on the internal network.
Technical details
This vulnerability in Sendmail involves an arbitrary command execution flaw during the handling of bounced emails. By providing a malformed 'MAIL FROM' address and an invalid 'RCPT TO' address via the SMTP protocol, an attacker can force the mailer to generate a bounce message. Due to improper sanitization or handling of the sender address, the bounce process can be manipulated to pipe the message into an arbitrary program. Since Sendmail often runs with high privileges, this allows a remote, unauthenticated attacker to execute commands with root authority on the host system.
Affected products
- Sendmail Sendmail
Timeline
- 1995-08-17: disclosed