CVE-2016-1978

Use-after-free vulnerability in the ssl3_HandleECDHServerKeyExchange function in Mozilla Network Security Services (NSS) before 3.21, as used in Mozilla Firefox before 44.0, allows remote attackers to cause a denial of service or possibly have unspecified other impact by making an SSL (1) DHE or (2) ECDHE handshake at a time of high memory consumption.

Published: 2016-03-13 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-1978 is rated Moderate Risk (59.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.46%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-1978

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-30 2.26% 2.46% +0.20%
2 2025-12-07 2.75% 2.26% -0.49%
3 2025-07-10 — 2.75% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-1978

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 3.4 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2016-1978

OS Trackers for CVE-2016-1978

vendor priority summary link
debian not yet assigned CVE-2016-1978 not yet assigned priority: Debian including 1 source packages (nss), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-1978
gentoo normal CVE-2016-1978: 1 GLSA(s) (201605-06), 6 atom(s) (dev-libs/nspr, dev-libs/nss, mail-client/thunderbird, mail-client/thunderbird-bin, www-client/firefox, www-client/firefox-bin); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-1978
redhat medium — https://access.redhat.com/security/cve/CVE-2016-1978
suse high CVE-2016-1978 severity important: SUSE including 128 source package names (MozillaFirefox-38.7.0esr-36.3, MozillaFirefox-38.7.0esr-37.3, …), 415 product×package rows across 51 product lines (Image SLES12-SP5-Azure-BYOS, Image SLES12-SP5-Azure-Basic-On-Demand, … (51 product lines)): Fixed 415. https://www.suse.com/security/cve/CVE-2016-1978/
ubuntu medium CVE-2016-1978 medium priority: Ubuntu including 3 source packages (firefox, nss, thunderbird), 21 status rows across 7 suites (precise, trusty, upstream, wily, xenial, yakkety, zesty): released 15, not-affected 6. https://ubuntu.com/security/CVE-2016-1978

NVD evaluator notes for CVE-2016-1978

Comment: <a href="http://cwe.mitre.org/data/definitions/416.html">CWE-416: Use After Free</a>

Affected software / configurations for CVE-2016-1978

Vendor Product Version Raw CPE
mozilla firefox <= 43.0.4 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla network_security_services <= 3.20.1 cpe:2.3:a:mozilla:network_security_services:*:*:*:*:*:*:*:*

References for CVE-2016-1978

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00027.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00050.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00068.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00093.html
http://rhn.redhat.com/errata/RHSA-2016-0591.html
http://rhn.redhat.com/errata/RHSA-2016-0684.html
http://rhn.redhat.com/errata/RHSA-2016-0685.html
http://www.debian.org/security/2016/dsa-3688
http://www.mozilla.org/security/announce/2016/mfsa2016-15.html Vendor Advisory
http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
http://www.securityfocus.com/bid/84275
http://www.securityfocus.com/bid/91787
http://www.securitytracker.com/id/1035258
http://www.ubuntu.com/usn/USN-2973-1
https://bto.bluecoat.com/security-advisory/sa124
https://bugzilla.mozilla.org/show_bug.cgi?id=1209546
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21_release_notes
https://security.gentoo.org/glsa/201605-06
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