CVE-2011-1926: Command Injection

Published May 17, 2011
·
Updated

It was found, that Cyrus IMAP recognized IMAP, LMTP, NNTP and POP3 protocol commands during plaintex to TLS session switch (by TLS protocol initialization). A remote attacker could use this flaw to insert plaintext, protocol relevant, commands into TLS protocol initialization messages, leading to execution of these commands during the ciphertext protocol phase, potentially allowing the attacker to steal the victim's mail or authentication credentials.

References: [1] http://www.kb.cert.org/vuls/id/555316 [2] http://bugzilla.cyrusimap.org/showbug.cgi?id=3423

Relevant upstream patch: [3] http://git.cyrusimap.org/cyrus-imapd/patch/?id=523a91a5e86c8b9a27a138f04a3e3f2d8786f162

Other sources

The STARTTLS implementation in Cyrus IMAP Server before 2.4.7 does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted 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.

MITRE

Affected Software

35 affected components
cmu Cyrus Imap Server<=2.4.6
cmu Cyrus Imap Server=2.0.17
cmu Cyrus Imap Server=2.1.16
cmu Cyrus Imap Server=2.1.17
cmu Cyrus Imap Server=2.1.18
cmu Cyrus Imap Server=2.2.8
cmu Cyrus Imap Server=2.2.9
cmu Cyrus Imap Server=2.2.10
cmu Cyrus Imap Server=2.2.11
cmu Cyrus Imap Server=2.2.12
cmu Cyrus Imap Server=2.2.13
cmu Cyrus Imap Server=2.2.13p1
cmu Cyrus Imap Server=2.3.0
cmu Cyrus Imap Server=2.3.1
cmu Cyrus Imap Server=2.3.2
cmu Cyrus Imap Server=2.3.3
cmu Cyrus Imap Server=2.3.4
cmu Cyrus Imap Server=2.3.5
cmu Cyrus Imap Server=2.3.6
cmu Cyrus Imap Server=2.3.7
cmu Cyrus Imap Server=2.3.8
cmu Cyrus Imap Server=2.3.9
cmu Cyrus Imap Server=2.3.10
cmu Cyrus Imap Server=2.3.11
cmu Cyrus Imap Server=2.3.12
cmu Cyrus Imap Server=2.3.13
cmu Cyrus Imap Server=2.3.14
cmu Cyrus Imap Server=2.3.15
cmu Cyrus Imap Server=2.3.16
cmu Cyrus Imap Server=2.4.0
cmu Cyrus Imap Server=2.4.1
cmu Cyrus Imap Server=2.4.2
cmu Cyrus Imap Server=2.4.3
cmu Cyrus Imap Server=2.4.4
cmu Cyrus Imap Server=2.4.5

Event History

May 17, 2011
Data Sourced
09:39 AM
DescriptionSeverityAffected Software
May 23, 2011
CVE Published
via MITRE·10:00 PM
Data Sourced
via MITRE·10:00 PM
Description

Frequently Asked Questions

1

What is the severity of CVE-2011-1926?

CVE-2011-1926 has a moderate severity rating due to its potential to allow remote attackers to execute arbitrary commands during a TLS session.

2

How do I fix CVE-2011-1926?

To fix CVE-2011-1926, update Cyrus IMAP Server to version 2.4.6 or later, which addresses this vulnerability.

3

What versions of Cyrus IMAP Server are affected by CVE-2011-1926?

CVE-2011-1926 affects Cyrus IMAP Server versions 2.0.17 through 2.4.5.

4

Can CVE-2011-1926 be exploited remotely?

Yes, CVE-2011-1926 can be exploited remotely by attackers inserting malicious commands during the TLS handshake.

5

What are the potential consequences of CVE-2011-1926?

The consequences of CVE-2011-1926 may include unauthorized execution of commands resulting in data leakage or additional system compromise.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203