CVE-2019-11691

moderate-risk

Published 2019-07-23

A use-after-free vulnerability can occur when working with XMLHttpRequest (XHR) in an event loop, causing the XHR main thread to be called after it has been freed. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

Do I need to act?

0.52% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 9.8/10 Critical

NETWORK / LOW complexity

Affected Products (3)

Firefox

Firefox Esr

Thunderbird

Affected Vendors

Mozilla

References (8)

Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1542465

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2019-13/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2019-14/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2019-15/

Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1542465

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2019-13/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2019-14/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2019-15/

/ 100

moderate-risk

Severity 32/34 · Critical

Exploitability 2/34 · Minimal

Exposure 9/34 · Low