CVE-2018-18505

An earlier fix for an Inter-process Communication (IPC) vulnerability, CVE-2011-3079, added authentication to communication between IPC endpoints and server parents during IPC process creation. This authentication is insufficient for channels created after the IPC process is started, leading to the authentication not being correctly applied to later channels. This could allow for a sandbox escape through IPC channels due to lack of message validation in the listener process. This vulnerability affects Thunderbird < 60.5, Firefox ESR < 60.5, and Firefox < 65.

Published: 2019-02-05 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-18505 is rated High Risk (74.1/100): CVSS Critical severity, with high exploitation likelihood (EPSS 4.54%, 90th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.49% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize 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-2018-18505

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 2026-06-15 2.04% 4.54% +2.49%
2 2026-05-29 3.18% 2.04% -1.14%
3 2026-05-26 3.18%

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-18505

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.
3.9 6.0 [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-2018-18505

OS Trackers for CVE-2018-18505

vendor priority summary link
alpine CVE-2018-18505: 1 source package rows (firefox-esr); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2018-18505
debian not yet assigned CVE-2018-18505 not yet assigned priority: Debian including 3 source packages (firefox, firefox-esr, thunderbird), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. https://security-tracker.debian.org/tracker/CVE-2018-18505
gentoo normal CVE-2018-18505: 2 GLSA(s) (201903-04, 201904-07), 4 atom(s) (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-2018-18505
redhat high https://access.redhat.com/security/cve/CVE-2018-18505
suse medium CVE-2018-18505 severity moderate: SUSE including 184 source package names (1.0.0.1862.1.5.2:libfreebl3-3.41.1-3.13.1, 1.0.0.1862.1.5.2:libsoftokn3-3.41.1-3.13.1, …), 743 product×package rows across 122 product lines (Container bci/openjdk, Container bci/openjdk-devel, … (122 product lines)): Fixed 694, Known Not Affected 49. https://www.suse.com/security/cve/CVE-2018-18505/
ubuntu medium CVE-2018-18505 medium priority: Ubuntu including 5 source packages (firefox, mozjs38, mozjs52, mozjs60, thunderbird), 80 status rows across 16 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 35, released 32, ignored 13. https://ubuntu.com/security/CVE-2018-18505

Affected software / configurations for CVE-2018-18505

Vendor Product Version Raw CPE
mozilla firefox < 60.5.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox < 65.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla thunderbird < 60.5.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

References for CVE-2018-18505

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00021.html
http://www.securityfocus.com/bid/106781 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2019:0218 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0219 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0269 Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0270 Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1087565 Issue Tracking Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00025.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/02/msg00024.html Mailing List Third Party Advisory
https://security.gentoo.org/glsa/201903-04 Third Party Advisory
https://security.gentoo.org/glsa/201904-07 Third Party Advisory
https://usn.ubuntu.com/3874-1/ Third Party Advisory
https://usn.ubuntu.com/3897-1/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4376 Third Party Advisory
https://www.debian.org/security/2019/dsa-4392 Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2019-01/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-02/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-03/ Vendor Advisory
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