A use-after-free vulnerability can occur in the Fetch API when the worker or the associated window are freed when still in use, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

No CVSS v4.0

No CVSS v3.1

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

Access Vector Network

Access Complexity Low

Authentication None

Confidentiality Impact Partial

Integrity Impact Partial

Availability Impact Partial

This CVE is not in the KEV list.

The EPSS score is 0.02442.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Mozilla Firefox affected
Version Status Constraints
unspecified affected < 56
Mozilla Firefox ESR affected
Version Status Constraints
unspecified affected < 52.4
Mozilla Thunderbird affected
Version Status Constraints
unspecified affected < 52.4

Configuration 1 [-]

OR cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

Configuration 2 [-]

OR cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_desktop:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:5.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

Configuration 3 [-]

cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

Configuration 4 [-]

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

Configuration 5 [-]

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
Package CPE Advisory Released Date
Red Hat Enterprise Linux 6
firefox-0:52.4.0-1.el6_9 cpe:/o:redhat:enterprise_linux:6 RHSA-2017:2831 2017-09-28T00:00:00Z
thunderbird-0:52.4.0-2.el6_9 cpe:/o:redhat:enterprise_linux:6 RHSA-2017:2885 2017-10-11T00:00:00Z
Red Hat Enterprise Linux 7
firefox-0:52.4.0-1.el7_4 cpe:/o:redhat:enterprise_linux:7 RHSA-2017:2831 2017-09-28T00:00:00Z
thunderbird-0:52.4.0-2.el7_4 cpe:/o:redhat:enterprise_linux:7 RHSA-2017:2885 2017-10-11T00:00:00Z

No data.

Project Subscriptions

Vendors Products
Debian Subscribe
Debian Linux Subscribe
Mozilla Subscribe
Firefox Subscribe
Thunderbird Subscribe
Redhat Subscribe
Enterprise Linux Subscribe
Enterprise Linux Desktop Subscribe
Enterprise Linux Server Subscribe
Enterprise Linux Server Aus Subscribe
Enterprise Linux Server Eus Subscribe
Enterprise Linux Workstation Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-1118-1 firefox-esr security update
Debian DLA Debian DLA DLA-1153-1 icedove/thunderbird security update
Debian DSA Debian DSA DSA-3987-1 firefox-esr security update
Debian DSA Debian DSA DSA-4014-1 thunderbird security update
EUVD EUVD EUVD-2017-16768 A use-after-free vulnerability can occur in the Fetch API when the worker or the associated window are freed when still in use, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.
Ubuntu USN Ubuntu USN USN-3435-1 Firefox vulnerabilities
Ubuntu USN Ubuntu USN USN-3436-1 Thunderbird vulnerabilities
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
http://www.securityfocus.com/bid/101055 cve-icon cve-icon
http://www.securitytracker.com/id/1039465 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2017:2831 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2017:2885 cve-icon cve-icon
https://bugzilla.mozilla.org/show_bug.cgi?id=1371889 cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2017/11/msg00000.html cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2017-7793 cve-icon
https://security.gentoo.org/glsa/201803-14 cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2017-7793 cve-icon
https://www.debian.org/security/2017/dsa-3987 cve-icon cve-icon
https://www.debian.org/security/2017/dsa-4014 cve-icon cve-icon
https://www.mozilla.org/en-US/security/advisories/mfsa2017-22/#CVE-2017-7793 cve-icon
https://www.mozilla.org/security/advisories/mfsa2017-21/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2017-22/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2017-23/ cve-icon cve-icon
History

Tue, 25 Nov 2025 18:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
Vendors & Products Mozilla firefox Esr

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2024-08-05T16:12:28.398Z

Reserved: 2017-04-12T00:00:00

Link: CVE-2017-7793

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2018-06-11T21:29:09.500

Modified: 2025-11-25T17:50:16.803

Link: CVE-2017-7793

cve-icon Redhat

Severity : Important

Publid Date: 2017-09-28T00:00:00Z

Links: CVE-2017-7793 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses