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Vulnerability record · CVE-2011-1926 · published 23 May 2011

CVE-2011-1926: Cmu cyrus imap server permissions and access controls vulnerability

Cmu · Cyrus Imap Server

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.

5.1 CVSS 2.0 Medium EPSS 4.0% · top 9.8% CWE-264 · Permissions and access controls
5.1CVSS 2.0 base score
4.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
40References
16 Jun 2026Last modified by NVD

Description

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.

AV:N/AC:H/Au:N/C:P/I:P/A:P

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://bugzilla.cyrusimap.org/show_bug.cgi?id=3423 Patch
http://bugzilla.cyrusimap.org/show_bug.cgi?id=3424 Patch
http://git.cyrusimap.org/cyrus-imapd/patch/?id=523a91a5e86c8b9a27a138f04a3e3f2d8786f162 Patch
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061374.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061415.html
http://openwall.com/lists/oss-security/2011/05/17/15 Patch
http://openwall.com/lists/oss-security/2011/05/17/2 Patch
http://secunia.com/advisories/44670
http://secunia.com/advisories/44876
http://secunia.com/advisories/44913
http://secunia.com/advisories/44928
http://www.cyrusimap.org/docs/cyrus-imapd/2.4.7/changes.php
http://www.debian.org/security/2011/dsa-2242
http://www.debian.org/security/2011/dsa-2258
http://www.kb.cert.org/vuls/id/555316 US Government Resource
http://www.mandriva.com/security/advisories?name=MDVSA-2011:100
http://www.redhat.com/support/errata/RHSA-2011-0859.html
http://www.securitytracker.com/id?1025625
https://bugzilla.redhat.com/show_bug.cgi?id=705288 Patch
https://exchange.xforce.ibmcloud.com/vulnerabilities/67867
http://bugzilla.cyrusimap.org/show_bug.cgi?id=3423 Patch
http://bugzilla.cyrusimap.org/show_bug.cgi?id=3424 Patch
http://git.cyrusimap.org/cyrus-imapd/patch/?id=523a91a5e86c8b9a27a138f04a3e3f2d8786f162 Patch
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061374.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-June/061415.html
http://openwall.com/lists/oss-security/2011/05/17/15 Patch
http://openwall.com/lists/oss-security/2011/05/17/2 Patch
http://secunia.com/advisories/44670
http://secunia.com/advisories/44876
http://secunia.com/advisories/44913
http://secunia.com/advisories/44928
http://www.cyrusimap.org/docs/cyrus-imapd/2.4.7/changes.php
http://www.debian.org/security/2011/dsa-2242
http://www.debian.org/security/2011/dsa-2258
http://www.kb.cert.org/vuls/id/555316 US Government Resource
http://www.mandriva.com/security/advisories?name=MDVSA-2011:100
http://www.redhat.com/support/errata/RHSA-2011-0859.html
http://www.securitytracker.com/id?1025625
https://bugzilla.redhat.com/show_bug.cgi?id=705288 Patch
https://exchange.xforce.ibmcloud.com/vulnerabilities/67867

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2011-1926), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.