Vulnerability record · CVE-2011-0411 · published 16 March 2011
CVE-2011-0411: Postfix permissions and access controls vulnerability
Postfix · Postfix
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.
Description
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.
AV:N/AC:M/Au:N/C:P/I:P/A:P
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
Track CVE-2011-0411 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2011-0411), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
