CVE-2016-10027

Name: CVE-2016-10027
Creator: NVD / NIST
Published: 2017-01-12T23:59:00.197+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10EPSS 1.51%

Last modified Jun 17, 2026

CVE-2016-10027 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. Race condition in the XMPP library in Smack before 4.1.9, when the SecurityMode.required TLS setting has been set, allows man-in-the-middle attackers to bypass TLS protections and trigger use of cleartext for client authentication by stripping the "starttls" feature from a server response.. EPSS estimates a 1.51% chance of exploitation in the next 30 days.

Description

Race condition in the XMPP library in Smack before 4.1.9, when the SecurityMode.required TLS setting has been set, allows man-in-the-middle attackers to bypass TLS protections and trigger use of cleartext for client authentication by stripping the "starttls" feature from a server response.

Metrics

CVSS 3.1

5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

1.51%

71.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Igniterealtime	Smack	< 4.1.9
Fedoraproject	Fedora	25

References

http://www.openwall.com/lists/oss-security/2016/12/22/12Mailing List, Patch, Third Party Advisory
http://www.securityfocus.com/bid/95129Third Party Advisory, VDB Entry
https://community.igniterealtime.org/blogs/ignite/2016/11/22/smack-security-advisory-2016-11-22Vendor Advisory
https://github.com/igniterealtime/Smack/commit/059ee99ba0d5ff7758829acf5a9aeede09ec820bPatch, Third Party Advisory
https://github.com/igniterealtime/Smack/commit/a9d5cd4a611f47123f9561bc5a81a4555fe7cb04Patch, Third Party Advisory
https://issues.igniterealtime.org/projects/SMACK/issues/SMACK-739Issue Tracking, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J4WXAZ4JVJXHMEDDXJVWJHPVBF5QCTZF/
http://www.openwall.com/lists/oss-security/2016/12/22/12Mailing List, Patch, Third Party Advisory
http://www.securityfocus.com/bid/95129Third Party Advisory, VDB Entry
https://community.igniterealtime.org/blogs/ignite/2016/11/22/smack-security-advisory-2016-11-22Vendor Advisory
https://github.com/igniterealtime/Smack/commit/059ee99ba0d5ff7758829acf5a9aeede09ec820bPatch, Third Party Advisory
https://github.com/igniterealtime/Smack/commit/a9d5cd4a611f47123f9561bc5a81a4555fe7cb04Patch, Third Party Advisory
https://issues.igniterealtime.org/projects/SMACK/issues/SMACK-739Issue Tracking, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J4WXAZ4JVJXHMEDDXJVWJHPVBF5QCTZF/

Timeline

Published: Jan 12, 2017
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2016-10027?

How severe is CVE-2016-10027?

CVE-2016-10027 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 1.51% probability of exploitation in the next 30 days.

How do I fix CVE-2016-10027?

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-2016-10027?

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

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Source: NVD / NIST