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CentOS Linux: CVE-2021-38507: Important: firefox security update (Multiple Advisories)

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CentOS Linux: CVE-2021-38507: Important: firefox security update (Multiple Advisories)

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
11/03/2021
Created
11/10/2021
Added
11/09/2021
Modified
05/25/2023

Description

The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP address (e.g. port 8443) did not opt-in to opportunistic encryption; a network attacker could forward a connection from the browser to port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. This was resolved by disabling the Opportunistic Encryption feature, which had low usage. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Solution(s)

  • centos-upgrade-firefox
  • centos-upgrade-firefox-debuginfo
  • centos-upgrade-firefox-debugsource
  • centos-upgrade-thunderbird
  • centos-upgrade-thunderbird-debuginfo
  • centos-upgrade-thunderbird-debugsource

References

  • DSA-5026
  • DSA-5034
  • CVE-2021-38507

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