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.
References
Configurations
Configuration 1 (hide)
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Configuration 2 (hide)
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History
21 Nov 2024, 06:17
Type | Values Removed | Values Added |
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References | () https://bugzilla.mozilla.org/show_bug.cgi?id=1730935 - Issue Tracking, Permissions Required, Vendor Advisory | |
References | () https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html - Mailing List, Third Party Advisory | |
References | () https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html - Mailing List, Third Party Advisory | |
References | () https://security.gentoo.org/glsa/202202-03 - Third Party Advisory | |
References | () https://security.gentoo.org/glsa/202208-14 - Third Party Advisory | |
References | () https://www.debian.org/security/2021/dsa-5026 - Third Party Advisory | |
References | () https://www.debian.org/security/2022/dsa-5034 - Third Party Advisory | |
References | () https://www.mozilla.org/security/advisories/mfsa2021-48/ - Vendor Advisory | |
References | () https://www.mozilla.org/security/advisories/mfsa2021-49/ - Vendor Advisory | |
References | () https://www.mozilla.org/security/advisories/mfsa2021-50/ - Vendor Advisory |
Information
Published : 2021-12-08 22:15
Updated : 2024-11-21 06:17
NVD link : CVE-2021-38507
Mitre link : CVE-2021-38507
CVE.ORG link : CVE-2021-38507
JSON object : View
Products Affected
mozilla
- thunderbird
- firefox
- firefox_esr
debian
- debian_linux
CWE
CWE-346
Origin Validation Error