Track vulnerabilities like this one. Sign up free to get alerted when software you use is affected.

CVE-2018-5092: Firefox before 58 may free web worker thread too soon

CVE-2018-5092 · published 8 years ago

Summary

Firefox versions earlier than 58 can release the memory for a background web worker before the main program finishes cancelling a download. This can cause the browser to crash or behave unpredictably, especially on Ubuntu systems that ship these older Firefox versions. Updating Firefox to the latest version fixes the issue.

What to do

The CVE record does not list a fixed version. Check the vendor's site or the advisory links below - a fix may already be released.

Affected software

Vendor	Product	Affected versions
mozilla	firefox	<= 57.0.4 `cpe:2.3:a:mozilla:firefox::::::::`
canonical	ubuntu_linux	14.04 16.04 17.10 `cpe:2.3:o:canonical:ubuntu_linux:14.04::::lts:::`

Original advisory text

A use-after-free vulnerability can occur when the thread for a Web Worker is freed from memory prematurely instead of from memory in the main thread while cancelling fetch operations. This vulnerab...

References

http://www.securityfocus.com/bid/102786 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1040270 Third Party Advisory VDB Entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1418074 Issue Tracking Permissions Required
https://usn.ubuntu.com/3544-1/ Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2018-02/ Vendor Advisory

Fix within

Internet-facing 3 days

Internal 60 days

Not known to be exploited
Can be exploited automatically (estimated)
Gives an attacker full control (estimated)

Severity

9.8 Critical

Exploitation

2% chance of attack within 30 days

Type

CWE-416Use After Free

Timeline

Published11 Jun 2018

Updated3 Nov 2026

First seen29 Sep 2026

Sources

CVE-2018-5092 · NVD

Track software like this

Free during beta