HOME VULNERABILITIESCVE-2015-2721

MEDIUM

CVE-2015-2721

CWE-310Published: July 6, 2015· Updated: Jun 17, 2026

4.3

CVSS v3.1

Official 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.

Technical Analysis

CVE-2015-2721 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityM

Privileges Req.

User Interaction

Scope

Impact

ConfidentialityNone

IntegrityP

AvailabilityNone

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

Affected Vendors & Products

Canonical1 product(s)

ubuntu linux

Debian1 product(s)

debian linux

Mozilla4 product(s)

network security servicesfirefoxfirefox esrthunderbird

novell3 product(s)

suse linux enterprise software development kitsuse linux enterprise desktopsuse linux enterprise server

Oracle2 product(s)

solarisvm server

Source: NVD CPE · 30 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2015-07/msg00033.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2015-07/msg00034.html

ADVISORYhttp://www.debian.org/security/2015/dsa-3324

ADVISORYhttp://www.debian.org/security/2015/dsa-3336

ADVISORYhttp://www.mozilla.org/security/announce/2015/mfsa2015-71.html

ADVISORYhttp://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html

ADVISORYhttp://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html

ADVISORYhttp://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html

ADVISORYhttp://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html

ADVISORYhttp://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html

ADVISORYhttp://www.securityfocus.com/bid/91787

ADVISORYhttp://www.ubuntu.com/usn/USN-2673-1

ADVISORYhttps://bugzilla.mozilla.org/show_bug.cgi?id=1086145

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2015-07/msg00033.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2015-07/msg00034.html

ADVISORYhttp://www.debian.org/security/2015/dsa-3324

ADVISORYhttp://www.debian.org/security/2015/dsa-3336

ADVISORYhttp://www.mozilla.org/security/announce/2015/mfsa2015-71.html

ADVISORYhttp://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html

ADVISORYhttp://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html

ADVISORYhttp://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html

ADVISORYhttp://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html

ADVISORYhttp://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html

ADVISORYhttp://www.securityfocus.com/bid/91787

ADVISORYhttp://www.ubuntu.com/usn/USN-2673-1

ADVISORYhttps://bugzilla.mozilla.org/show_bug.cgi?id=1086145

All References (58)

→

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

Quick Facts

CVE IDCVE-2015-2721

CVSS Score4.3 / 10

SeverityMEDIUM

WeaknessCWE-310

CISA KEVNo

Affected5 vendor(s)

PublishedJul 6, 2015

Related CVEs (CWE-310)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2015-2721 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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