CVE-2011-2165

Name: CVE-2011-2165
Creator: NVD / NIST
Published: 2011-05-23T22:55:01.553+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 5.16%

Last modified Jun 16, 2026

CVE-2011-2165 is a vulnerability of currently unknown severity. The STARTTLS implementation in WatchGuard XCS 9.0 and 9.1 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, a similar issue to CVE-2011-0411.. EPSS estimates a 5.16% chance of exploitation in the next 30 days.

Description

The STARTTLS implementation in WatchGuard XCS 9.0 and 9.1 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, a similar issue to CVE-2011-0411.

Metrics

EPSS Probability

5.16%

91.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-264

Affected Software

Vendor	Product	Versions
Watchguard	Xcs	9.0
Watchguard	Xcs	9.1

References

Timeline

Published: May 23, 2011
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2011-2165?

How severe is CVE-2011-2165?

Severity scoring for CVE-2011-2165 is pending analysis. The EPSS model estimates a 5.16% probability of exploitation in the next 30 days.

How do I fix CVE-2011-2165?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2011-2165?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST