CVE-2015-2721

Public Exploit

Description

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.

Category

4.3
CVSS
Severity: Medium
CVSS 2.0 •
EPSS 0.90% Top 30%
Vendor Advisory opensuse.org Vendor Advisory opensuse.org Vendor Advisory gentoo.org Vendor Advisory gentoo.org Vendor Advisory debian.org Vendor Advisory redhat.com Vendor Advisory debian.org Vendor Advisory ubuntu.com Vendor Advisory ubuntu.com Vendor Advisory opensuse.org Vendor Advisory opensuse.org Vendor Advisory redhat.com Vendor Advisory ubuntu.com Vendor Advisory opensuse.org Vendor Advisory ubuntu.com Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html third party advisory
http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00025.html vendor advisory
http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00033.html third party advisory vendor advisory
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.19_release_notes release notes
http://www.securityfocus.com/bid/83398 vdb entry
https://security.gentoo.org/glsa/201512-10 vendor advisory
https://security.gentoo.org/glsa/201701-46 vendor advisory
http://www.debian.org/security/2015/dsa-3336 third party advisory vendor advisory
http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html third party advisory
http://www.securityfocus.com/bid/75541 vdb entry
http://rhn.redhat.com/errata/RHSA-2015-1185.html vendor advisory
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html third party advisory
http://www.debian.org/security/2015/dsa-3324 third party advisory vendor advisory
http://www.ubuntu.com/usn/USN-2672-1 vendor advisory
http://www.ubuntu.com/usn/USN-2673-1 third party advisory vendor advisory
http://www.securitytracker.com/id/1032784 vdb entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1086145 issue tracking vendor advisory exploit vdb entry
http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00034.html third party advisory vendor advisory
http://www.mozilla.org/security/announce/2015/mfsa2015-71.html vendor advisory
http://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html third party advisory
http://www.securityfocus.com/bid/91787 vdb entry third party advisory
http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00031.html vendor advisory
http://rhn.redhat.com/errata/RHSA-2015-1664.html vendor advisory
http://www.ubuntu.com/usn/USN-2656-1 vendor advisory
http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00021.html vendor advisory
https://smacktls.com technical description
http://www.securitytracker.com/id/1032783 vdb entry
http://www.ubuntu.com/usn/USN-2656-2 vendor advisory
http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html third party advisory

Frequently Asked Questions

What is the severity of CVE-2015-2721?
CVE-2015-2721 has been scored as a medium severity vulnerability.
How to fix CVE-2015-2721?
To fix CVE-2015-2721, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2015-2721 being actively exploited in the wild?
It is possible that CVE-2015-2721 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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