CVE-2016-1979

Use-after-free vulnerability in the PK11_ImportDERPrivateKeyInfoAndReturnKey function in Mozilla Network Security Services (NSS) before 3.21.1, as used in Mozilla Firefox before 45.0, allows remote attackers to cause a denial of service or possibly have unspecified other impact via crafted key data with DER encoding.

Published: 2016-03-13 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-1979 is rated Moderate Risk (60/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.71%). Mandatory action: 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-2016-1979

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 2025-12-07 0.89% 0.71% -0.19%
2 2025-03-30 2.92% 0.89% -2.02%
3 2025-03-29 2.92%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-1979

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/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:M)
Exploitation needs some favorable conditions, but not exceptional ones.
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.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2016-1979

OS Trackers for CVE-2016-1979

vendor priority summary link
debian not yet assigned CVE-2016-1979 not yet assigned priority: Debian including 3 source packages (firefox, firefox-esr, nss), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. https://security-tracker.debian.org/tracker/CVE-2016-1979
gentoo normal CVE-2016-1979: 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-2016-1979
redhat medium https://access.redhat.com/security/cve/CVE-2016-1979
suse high CVE-2016-1979 severity important: SUSE including 614 source package names (MozillaFirefox-102.11.0-150200.152.87.1, MozillaFirefox-115.10.0-150200.152.134.1, …), 927 product×package rows across 90 product lines (Image SLES12-SP5-Azure-BYOS, Image SLES12-SP5-Azure-Basic-On-Demand, … (90 product lines)): Fixed 770, Known Affected 157. https://www.suse.com/security/cve/CVE-2016-1979/
ubuntu medium CVE-2016-1979 medium priority: Ubuntu including 3 source packages (firefox, nss, thunderbird), 21 status rows across 7 suites (precise, trusty, upstream, wily, xenial, yakkety, zesty): released 12, not-affected 9. https://ubuntu.com/security/CVE-2016-1979

NVD evaluator notes for CVE-2016-1979

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

Affected software / configurations for CVE-2016-1979

Vendor Product Version Raw CPE
mozilla firefox <= 44.0.2 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla network_security_services <= 3.21 cpe:2.3:a:mozilla:network_security_services:*:*:*:*:*:*:*:*

References for CVE-2016-1979

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00027.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00029.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00031.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-3576
http://www.debian.org/security/2016/dsa-3688
http://www.mozilla.org/security/announce/2016/mfsa2016-36.html Vendor Advisory
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.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/84221
http://www.securitytracker.com/id/1035215
http://www.ubuntu.com/usn/USN-2973-1
https://bto.bluecoat.com/security-advisory/sa124
https://bugzilla.mozilla.org/show_bug.cgi?id=1185033
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.21.1_release_notes
https://security.gentoo.org/glsa/201605-06
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