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Fencer Vulns
high 8.8

CVE-2016-5258 json

Use-after-free vulnerability in the WebRTC socket thread in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote atta…

published 2016-08-05 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-6209

cvss
8.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.3%
EPSS 3.3% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

Use-after-free vulnerability in the WebRTC socket thread in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to execute arbitrary code by leveraging incorrect free operations on DTLS objects during the shutdown of a WebRTC session.

Patch / fix

  • firefox-esr Debian 14, Debian 13, Debian 12 45.3.0esr-1

debian advisories DEBIAN-CVE-2016-5258

  • firefox Ubuntu 14.04 LTS 48.0+build2-0ubuntu0.14.04.1
  • firefox Ubuntu 16.04 LTS 48.0+build2-0ubuntu0.16.04.1

ubuntu advisories UBUNTU-CVE-2016-5258

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • firefox RHEL 5 45.3.0-1.el5_11
  • firefox RHEL 6 45.3.0-1.el6_8
  • firefox RHEL 7 45.3.0-1.el7_2

red hat advisories RHSA-2016:1551

  • MozillaFirefox SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +6 more 45.3.0esr-50.1
  • MozillaFirefox SLES for SAP 12 SP1, SLES for SAP 12, SLES 12-LTSS +3 more 45.3.0esr-78.1
  • mozilla-nss SLES 11 SP2-LTSS 3.21.1-26.2
  • mozilla-nspr SLES 11 SP2-LTSS 4.12-25.2
  • MozillaFirefox SLES 11 SP2-LTSS 45.3.0esr-48.1
  • firefox-fontconfig SLES 11 SP2-LTSS 2.11.0-4.2
  • MozillaFirefox-branding-SLED SLES 11 SP2-LTSS 45.0-20.38

suse advisories SUSE-SU-2016:2195-1SUSE-SU-2016:2131-1SUSE-SU-2016:2061-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1
  • MozillaThunderbird openSUSE Tumbleweed 45.5.1-1.1
  • MozillaThunderbird Package Hub 12 45.3.0-9.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10071-1openSUSE-SU-2024:10230-1openSUSE-SU-2016:2253-1openSUSE-SU-2016:2254-1

  • firefox Arch Linux 48.0.1-1

arch linux advisories AVG-935

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-5258 updated cvss 8.8

Mozilla: Use-after-free in DTLS during WebRTC session shutdown (MFSA 2016-72)

  • Red Hat Enterprise Linux (v. 5 server) firefox 45.3.0-1.el5_11 Red Hat Enterprise Linux Client (v. 7) firefox 45.3.0-1.el7_2 Red Hat Enterprise Linux Client Optional (v. 7) firefox 45.3.0-1.el7_2 Red Hat Enterprise Linux Desktop (v. 5 client) firefox 45.3.0-1.el5_11 Red Hat Enterprise Linux Desktop (v. 6) firefox 45.3.0-1.el6_8 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 45.3.0-1.el6_8
    +9 more products
    Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 45.3.0-1.el6_8 Red Hat Enterprise Linux Server (v. 6) firefox 45.3.0-1.el6_8 Red Hat Enterprise Linux Server (v. 7) firefox 45.3.0-1.el7_2 Red Hat Enterprise Linux Server Optional (v. 6) firefox 45.3.0-1.el6_8 Red Hat Enterprise Linux Server Optional (v. 7) firefox 45.3.0-1.el7_2 Red Hat Enterprise Linux Workstation (v. 6) firefox 45.3.0-1.el6_8 Red Hat Enterprise Linux Workstation (v. 7) firefox 45.3.0-1.el7_2 Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 45.3.0-1.el6_8 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 45.3.0-1.el7_2
    fixed: vendor fix RHSA-2016:1551
  • Red Hat Enterprise Linux 5 thunderbird Red Hat Enterprise Linux 6 thunderbird Red Hat Enterprise Linux 7 thunderbird
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.26% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1279146 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.