Public Date:
674814: CVE-2011-0411 postfix: SMTP commands injection during plaintext to TLS session switch

The MITRE CVE dictionary describes this issue as:

The STARTTLS implementation in Postfix 2.4.x before 2.4.16, 2.5.x before 2.5.12, 2.6.x before 2.6.9, and 2.7.x before 2.7.3 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack.

Find out more about CVE-2011-0411 from the MITRE CVE dictionary dictionary and NIST NVD.


This issue affected postfix packages in Red Hat Enterprise Linux 4, 5, and 6. It was corrected via RHSA-2011:0422 and RHSA-2011:0423.

This issue did not affect the versions of sendmail as shipped with Red Hat Enterprise Linux 3, 4, 5, or 6, and the versions of exim as shipped with Red Hat Enterprise Linux 4 and 5.

CVSS v2 metrics

Base Score 4
Base Metrics AV:N/AC:H/Au:N/C:P/I:P/A:N
Access Vector Network
Access Complexity High
Authentication None
Confidentiality Impact Partial
Integrity Impact Partial
Availability Impact None

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux 4 (postfix) RHSA-2011:0422 2011-04-06
Red Hat Enterprise Linux 5 (postfix) RHSA-2011:0422 2011-04-06
Red Hat Enterprise Linux 6 (postfix) RHSA-2011:0423 2011-04-06


Red Hat would like to thank the CERT/CC for reporting CVE-2011-0411. The CERT/CC acknowledges Wietse Venema as the original reporter.
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