{"containers":{"cna":{"affected":[{"product":"Firefox","vendor":"Mozilla","versions":[{"lessThan":"94","status":"affected","version":"unspecified","versionType":"custom"}]},{"product":"Thunderbird","vendor":"Mozilla","versions":[{"lessThan":"91.3","status":"affected","version":"unspecified","versionType":"custom"}]},{"product":"Firefox ESR","vendor":"Mozilla","versions":[{"lessThan":"91.3","status":"affected","version":"unspecified","versionType":"custom"}]}],"descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"description":"Opportunistic Encryption in HTTP2 could be used to bypass the Same-Origin-Policy on services hosted on other ports","lang":"en","type":"text"}]}],"providerMetadata":{"dateUpdated":"2022-08-10T05:11:20.000Z","orgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","shortName":"mozilla"},"references":[{"tags":["x_refsource_MISC"],"url":"https://www.mozilla.org/security/advisories/mfsa2021-49/"},{"tags":["x_refsource_MISC"],"url":"https://www.mozilla.org/security/advisories/mfsa2021-50/"},{"tags":["x_refsource_MISC"],"url":"https://www.mozilla.org/security/advisories/mfsa2021-48/"},{"tags":["x_refsource_MISC"],"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1730935"},{"name":"DSA-5026","tags":["vendor-advisory","x_refsource_DEBIAN"],"url":"https://www.debian.org/security/2021/dsa-5026"},{"name":"[debian-lts-announce] 20211229 [SECURITY] [DLA 2863-1] firefox-esr security update","tags":["mailing-list","x_refsource_MLIST"],"url":"https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html"},{"name":"DSA-5034","tags":["vendor-advisory","x_refsource_DEBIAN"],"url":"https://www.debian.org/security/2022/dsa-5034"},{"name":"[debian-lts-announce] 20220104 [SECURITY] [DLA 2874-1] thunderbird security update","tags":["mailing-list","x_refsource_MLIST"],"url":"https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html"},{"name":"GLSA-202202-03","tags":["vendor-advisory","x_refsource_GENTOO"],"url":"https://security.gentoo.org/glsa/202202-03"},{"name":"GLSA-202208-14","tags":["vendor-advisory","x_refsource_GENTOO"],"url":"https://security.gentoo.org/glsa/202208-14"}],"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"security@mozilla.org","ID":"CVE-2021-38507","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"Firefox","version":{"version_data":[{"version_affected":"<","version_value":"94"}]}},{"product_name":"Thunderbird","version":{"version_data":[{"version_affected":"<","version_value":"91.3"}]}},{"product_name":"Firefox ESR","version":{"version_data":[{"version_affected":"<","version_value":"91.3"}]}}]},"vendor_name":"Mozilla"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"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."}]},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"Opportunistic Encryption in HTTP2 could be used to bypass the Same-Origin-Policy on services hosted on other ports"}]}]},"references":{"reference_data":[{"name":"https://www.mozilla.org/security/advisories/mfsa2021-49/","refsource":"MISC","url":"https://www.mozilla.org/security/advisories/mfsa2021-49/"},{"name":"https://www.mozilla.org/security/advisories/mfsa2021-50/","refsource":"MISC","url":"https://www.mozilla.org/security/advisories/mfsa2021-50/"},{"name":"https://www.mozilla.org/security/advisories/mfsa2021-48/","refsource":"MISC","url":"https://www.mozilla.org/security/advisories/mfsa2021-48/"},{"name":"https://bugzilla.mozilla.org/show_bug.cgi?id=1730935","refsource":"MISC","url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1730935"},{"name":"DSA-5026","refsource":"DEBIAN","url":"https://www.debian.org/security/2021/dsa-5026"},{"name":"[debian-lts-announce] 20211229 [SECURITY] [DLA 2863-1] firefox-esr security update","refsource":"MLIST","url":"https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html"},{"name":"DSA-5034","refsource":"DEBIAN","url":"https://www.debian.org/security/2022/dsa-5034"},{"name":"[debian-lts-announce] 20220104 [SECURITY] [DLA 2874-1] thunderbird security update","refsource":"MLIST","url":"https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html"},{"name":"GLSA-202202-03","refsource":"GENTOO","url":"https://security.gentoo.org/glsa/202202-03"},{"name":"GLSA-202208-14","refsource":"GENTOO","url":"https://security.gentoo.org/glsa/202208-14"}]}}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T01:44:23.527Z"},"title":"CVE Program Container","references":[{"tags":["x_refsource_MISC","x_transferred"],"url":"https://www.mozilla.org/security/advisories/mfsa2021-49/"},{"tags":["x_refsource_MISC","x_transferred"],"url":"https://www.mozilla.org/security/advisories/mfsa2021-50/"},{"tags":["x_refsource_MISC","x_transferred"],"url":"https://www.mozilla.org/security/advisories/mfsa2021-48/"},{"tags":["x_refsource_MISC","x_transferred"],"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1730935"},{"name":"DSA-5026","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred"],"url":"https://www.debian.org/security/2021/dsa-5026"},{"name":"[debian-lts-announce] 20211229 [SECURITY] [DLA 2863-1] firefox-esr security update","tags":["mailing-list","x_refsource_MLIST","x_transferred"],"url":"https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html"},{"name":"DSA-5034","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred"],"url":"https://www.debian.org/security/2022/dsa-5034"},{"name":"[debian-lts-announce] 20220104 [SECURITY] [DLA 2874-1] thunderbird security update","tags":["mailing-list","x_refsource_MLIST","x_transferred"],"url":"https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html"},{"name":"GLSA-202202-03","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred"],"url":"https://security.gentoo.org/glsa/202202-03"},{"name":"GLSA-202208-14","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred"],"url":"https://security.gentoo.org/glsa/202208-14"}]}]},"cveMetadata":{"assignerOrgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","assignerShortName":"mozilla","cveId":"CVE-2021-38507","datePublished":"2021-12-08T21:21:41.000Z","dateReserved":"2021-08-10T00:00:00.000Z","dateUpdated":"2024-08-04T01:44:23.527Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.1"}