CVE-2019-11728

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-07-23 · updated 2026-06-17
Weakness: CWE-668

Description

The HTTP Alternative Services header, Alt-Svc, can be used by a malicious site to scan all TCP ports of any host that the accessible to a user when web content is loaded. This vulnerability affects Firefox < 68.

Affected products

Mozilla Firefox: before 68.0 — fixed in 68.0
openSUSE Leap: 15.0, 15.1

How to fix

Upgrade to a fixed version: Mozilla Firefox 68.0. Check the vendor advisory for mitigations.

References

http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1552993
https://security.gentoo.org/glsa/201908-12
https://www.mozilla.org/security/advisories/mfsa2019-21/
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1552993

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