CVE-2015-2721

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state machine, which allows man-in-the-middle attackers to defeat cryptographic protection mechanisms by blocking messages, as demonstrated by removing a forward-secrecy property by blocking a ServerKeyExchange message, aka a "SMACK SKIP-TLS" issue.

• CWE-310

• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00025.html
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00031.html
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00033.htmlThird Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00034.htmlThird Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00021.html
• http://rhn.redhat.com/errata/RHSA-2015-1185.html
• http://rhn.redhat.com/errata/RHSA-2015-1664.html
• http://www.debian.org/security/2015/dsa-3324Third Party Advisory
• http://www.debian.org/security/2015/dsa-3336Third Party Advisory
• http://www.mozilla.org/security/announce/2015/mfsa2015-71.htmlVendor Advisory
• http://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.htmlThird Party Advisory
• http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.htmlThird Party Advisory
• http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.htmlThird Party Advisory
• http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.htmlThird Party Advisory
• http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.htmlThird Party Advisory
• http://www.securityfocus.com/bid/75541
• http://www.securityfocus.com/bid/83398
• http://www.securityfocus.com/bid/91787Third Party Advisory
• http://www.securitytracker.com/id/1032783
• http://www.securitytracker.com/id/1032784
• http://www.ubuntu.com/usn/USN-2656-1
• http://www.ubuntu.com/usn/USN-2656-2
• http://www.ubuntu.com/usn/USN-2672-1
• http://www.ubuntu.com/usn/USN-2673-1Third Party Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1086145Exploit, Issue Tracking, VDB Entry, Vendor Advisory
• https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.19_release_notesRelease Notes
• https://security.gentoo.org/glsa/201512-10
• https://security.gentoo.org/glsa/201701-46
• https://smacktls.comTechnical Description
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00025.html
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00031.html
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00033.htmlThird Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00034.htmlThird Party Advisory
• http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00021.html
• http://rhn.redhat.com/errata/RHSA-2015-1185.html
• http://rhn.redhat.com/errata/RHSA-2015-1664.html
• http://www.debian.org/security/2015/dsa-3324Third Party Advisory
• http://www.debian.org/security/2015/dsa-3336Third Party Advisory
• http://www.mozilla.org/security/announce/2015/mfsa2015-71.htmlVendor Advisory
• http://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.htmlThird Party Advisory
• http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.htmlThird Party Advisory
• http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.htmlThird Party Advisory
• http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.htmlThird Party Advisory
• http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.htmlThird Party Advisory
• http://www.securityfocus.com/bid/75541
• http://www.securityfocus.com/bid/83398
• http://www.securityfocus.com/bid/91787Third Party Advisory
• http://www.securitytracker.com/id/1032783
• http://www.securitytracker.com/id/1032784
• http://www.ubuntu.com/usn/USN-2656-1
• http://www.ubuntu.com/usn/USN-2656-2
• http://www.ubuntu.com/usn/USN-2672-1
• http://www.ubuntu.com/usn/USN-2673-1Third Party Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1086145Exploit, Issue Tracking, VDB Entry, Vendor Advisory
• https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.19_release_notesRelease Notes
• https://security.gentoo.org/glsa/201512-10
• https://security.gentoo.org/glsa/201701-46
• https://smacktls.comTechnical Description

Published

Jul 6, 2015

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2015-2714Mozilla Firefox before 38.0 on Android does not properly res…
• CVE-2015-2715Race condition in the nsThreadManager::RegisterCurrentThread…
• CVE-2015-2716Buffer overflow in the XML parser in Mozilla Firefox before …
• CVE-2015-2717Integer overflow in libstagefright in Mozilla Firefox before…
• CVE-2015-2718The WebChannel.jsm module in Mozilla Firefox before 38.0 all…
• CVE-2015-2720The update implementation in Mozilla Firefox before 38.0 on …
• CVE-2015-2722Use-after-free vulnerability in the CanonicalizeXPCOMPartici…
• CVE-2015-2723Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultI…
• CVE-2015-2724Multiple unspecified vulnerabilities in the browser engine i…
• CVE-2015-2725Multiple unspecified vulnerabilities in the browser engine i…
• CVE-2015-2726Multiple unspecified vulnerabilities in the browser engine i…
• CVE-2015-2727Mozilla Firefox 38.0 and Firefox ESR 38.0 allow user-assiste…