What’s Vulnerable › Vulnerabilities
CVE-2015-2721
- Severity: medium (CVSS 4.3 v2.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.8% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2015-07-06 · updated 2026-06-17
- Weakness: CWE-310
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.
Affected products
- Canonical Ubuntu Linux: 12.04, 14.04, 14.10, 15.04
- Debian Linux: 7.0, 8.0
- Mozilla Network Security Services: 3.19
- Novell Suse Linux Enterprise Desktop: 12.0
- Novell Suse Linux Enterprise Server: 11-sp4, 12.0
- Novell Suse Linux Enterprise Software Development Kit: 12.0
- Oracle Corporation Solaris Operating System: 11.3
- Oracle Vm Server: 3.2
References
- 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.html
- http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00034.html
- 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-3324
- http://www.debian.org/security/2015/dsa-3336
- http://www.mozilla.org/security/announce/2015/mfsa2015-71.html
- http://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html
- http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
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