CVE-2021-38507
Vulnerability from cvelistv5
Published
2021-12-08 21:21
Modified
2024-08-04 01:44
Severity ?
Summary
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
security@mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=1730935Issue Tracking, Permissions Required, Vendor Advisory
security@mozilla.orghttps://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing List, Third Party Advisory
security@mozilla.orghttps://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
security@mozilla.orghttps://security.gentoo.org/glsa/202202-03Third Party Advisory
security@mozilla.orghttps://security.gentoo.org/glsa/202208-14Third Party Advisory
security@mozilla.orghttps://www.debian.org/security/2021/dsa-5026Third Party Advisory
security@mozilla.orghttps://www.debian.org/security/2022/dsa-5034Third Party Advisory
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-49/Vendor Advisory
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2021-50/Vendor Advisory
Impacted products
MozillaFirefox
MozillaThunderbird
MozillaFirefox ESR
Show details on NVD website

To clipboard 

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