Skip to content
Noroxi
CVE-2015-2721· NVD / CVE Program· CNA mozilla

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

Noroxi assessment

Priority: Monitor (action score 18/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 3.2% (FIRST EPSS); higher than 88.2% of all records.
  • Fixed version: nss (Debian:12) 2:3.19.1-1; nss (Debian:6.0) 3.12.8-1+squeeze12; icedove (Debian:7) 31.8.0-1~deb7u1.

Low priority for now. Upgrade to nss (Debian:12) 2:3.19.1-1; nss (Debian:6.0) 3.12.8-1+squeeze12; icedove (Debian:7) 31.8.0-1~deb7u1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 4.3 · v2.0—No exploit Fix available
Published
Jul 5, 2015
Updated
Jun 16, 2026
EPSS
3.2% · 88th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
17 / 40 · 4.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 3.2%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2015-2721

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for mozilla records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
mozillanetwork security services
mozillafirefox
mozillafirefox esr
mozillathunderbird
novellsuse linux enterprise software development kit
canonicalubuntu linux
debiandebian linux
novellsuse linux enterprise desktop
novellsuse linux enterprise server
oraclesolaris
oraclevm server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux12.04
  • canonical ubuntu linux14.04
  • canonical ubuntu linux14.10
  • canonical ubuntu linux15.04
  • debian debian linux7.0
  • debian debian linux8.0
  • mozilla network security services3.19
  • novell suse linux enterprise desktop12.0
  • novell suse linux enterprise server11
  • novell suse linux enterprise server12.0
  • novell suse linux enterprise software development kit12.0
  • oracle solaris11.3
  • oracle vm server3.2

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12nssbefore 2:3.19.1-12:3.19.1-1
Debian:6.0nssbefore 3.12.8-1+squeeze123.12.8-1+squeeze12
Debian:7icedovebefore 31.8.0-1~deb7u131.8.0-1~deb7u1
Debian:7iceweaselbefore 31.8.0esr-1~deb7u131.8.0esr-1~deb7u1
Debian:7nssbefore 2:3.14.5-1+deb7u52:3.14.5-1+deb7u5
Debian:8icedovebefore 31.8.0-1~deb8u131.8.0-1~deb8u1
Debian:8iceweaselbefore 31.8.0esr-1~deb8u131.8.0esr-1~deb8u1
Debian:8nssbefore 2:3.17.2-1.1+deb8u12:3.17.2-1.1+deb8u1
openSUSE:Tumbleweedmozilla-nssbefore 3.26.2-1.13.26.2-1.1
Red Hat:enterprise_linux:5::clientnssbefore 0:3.19.1-1.el5_110:3.19.1-1.el5_11
Red Hat:enterprise_linux:5::clientnss-debuginfobefore 0:3.19.1-1.el5_110:3.19.1-1.el5_11
Red Hat:enterprise_linux:5::clientnss-toolsbefore 0:3.19.1-1.el5_110:3.19.1-1.el5_11
Red Hat:enterprise_linux:5::client_workstationnss-develbefore 0:3.19.1-1.el5_110:3.19.1-1.el5_11
Red Hat:enterprise_linux:5::client_workstationnss-pkcs11-develbefore 0:3.19.1-1.el5_110:3.19.1-1.el5_11
Red Hat:enterprise_linux:6::clientnssbefore 0:3.19.1-3.el6_60:3.19.1-3.el6_6
Red Hat:enterprise_linux:6::clientnss-debuginfobefore 0:3.19.1-3.el6_60:3.19.1-3.el6_6
Red Hat:enterprise_linux:6::clientnss-develbefore 0:3.19.1-3.el6_60:3.19.1-3.el6_6
Red Hat:enterprise_linux:6::clientnss-pkcs11-develbefore 0:3.19.1-3.el6_60:3.19.1-3.el6_6
Red Hat:enterprise_linux:6::clientnss-sysinitbefore 0:3.19.1-3.el6_60:3.19.1-3.el6_6
Red Hat:enterprise_linux:6::clientnss-toolsbefore 0:3.19.1-3.el6_60:3.19.1-3.el6_6
Red Hat:enterprise_linux:6::clientnss-utilbefore 0:3.19.1-1.el6_60:3.19.1-1.el6_6
Red Hat:enterprise_linux:6::clientnss-util-debuginfobefore 0:3.19.1-1.el6_60:3.19.1-1.el6_6
Red Hat:enterprise_linux:6::clientnss-util-develbefore 0:3.19.1-1.el6_60:3.19.1-1.el6_6
Red Hat:enterprise_linux:7::clientnssbefore 0:3.19.1-3.el7_10:3.19.1-3.el7_1

+27

Same product

mozilla: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-5461Mozilla Network Security Services (NSS) before 3.21.4, 3.22.x through 3.28.x before 3.28.4, 3.29.x before 3.29.5, and 3.30.x before 3.30.1 a
    40Plan
  • CVE-2009-2404Heap-based buffer overflow in a regular-expression parser in Mozilla Network Security Services (NSS) before 3.12.3, as used in Firefox, Thun
    38Monitor
  • CVE-2018-12404A cached side channel attack during handshakes using RSA encryption could allow for the decryption of encrypted content.
    36Monitor
  • CVE-2016-2834Mozilla Network Security Services (NSS) before 3.23, as used in Mozilla Firefox before 47.0, allows remote attackers to cause a denial of se
    36Monitor
  • CVE-2016-1950Heap-based buffer overflow in Mozilla Network Security Services (NSS) before 3.19.2.3 and 3.20.x and 3.21.x before 3.21.1, as used in Mozill
    36Monitor
  • CVE-2015-7181The sec_asn1d_parse_leaf function in Mozilla Network Security Services (NSS) before 3.19.2.1 and 3.20.x before 3.20.1, as used in Firefox be
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:icedove31.8.0-1~deb7u1 · Debian:7Package registry (OSV)
debian:iceweasel31.8.0esr-1~deb7u1 · Debian:7Package registry (OSV)
debian:nss2:3.19.1-1 · Debian:12Package registry (OSV)
opensuse:mozilla-nss3.26.2-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:nss0:3.19.1-3.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-debuginfo0:3.19.1-3.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-devel0:3.19.1-3.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-pkcs11-devel0:3.19.1-3.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-sysinit0:3.19.1-3.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-tools0:3.19.1-3.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-util0:3.19.1-1.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-util-debuginfo0:3.19.1-1.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:nss-util-devel0:3.19.1-1.el6_6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
suse:firefox-gcc474.7.2_20130108-0.37.2 · SUSE:Linux Enterprise Server 11 SP1-LTSSPackage registry (OSV)
suse:mozilla-nspr4.10.8-0.5.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:mozilla-nss3.19.2_CKBI_1.98-0.10.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:MozillaFirefox31.8.0esr-0.10.1 · SUSE:Linux Enterprise Server 11 SP4Package registry (OSV)
suse:MozillaFirefox-branding-SLED31.0-0.5.7.11 · SUSE:Linux Enterprise Server 11 SP1-LTSSPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

    If successful

    Confidentiality
    none
    Integrity
    P · data or configuration can be modified
    Availability
    none
    Attack complexity
    M
    Confidentiality impact
    None
    Integrity impact
    P
    Availability impact
    None

    Weakness class (CWE)

    CWE-310 · Cryptographic Issues

    CVSS vector

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

    nvd-primary

    Attack context

    MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

    MITRE has no CAPEC/ATT&CK mapping for this CWE.

    Change log

    1. Fix✗ → ✓

    For records you follow, these changes also arrive as notifications. →

    References

    Show all references (19 more)

    Vendor advisories and official records. Exploit/PoC links are deliberately left out.

    All records