{"id":"UBUNTU-CVE-2021-36773","details":"uBlock Origin before 1.36.2 and nMatrix before 4.4.9 support an arbitrary depth of parameter nesting for strict blocking, which allows crafted web sites to cause a denial of service (unbounded recursion that can trigger memory consumption and a loss of all blocking functionality).","modified":"2025-10-24T04:50:26Z","published":"2021-07-18T04:15:00Z","upstream":["CVE-2021-36773"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-36773"},{"type":"REPORT","url":"https://github.com/vtriolet/writings/blob/main/posts/2021/ublock_origin_and_umatrix_denial_of_service.adoc"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-36773"}],"affected":[{"package":{"name":"ublock-origin","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/ublock-origin@1.6.6+dfsg-1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.6+dfsg-1","1.6.0+dfsg-1","1.6.6+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"xul-ext-ublock-origin","binary_version":"1.6.6+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}},{"package":{"name":"ublock-origin","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ublock-origin@1.13.8+dfsg-1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.13.8+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"chromium-ublock-origin","binary_version":"1.13.8+dfsg-1"},{"binary_name":"xul-ext-ublock-origin","binary_version":"1.13.8+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}},{"package":{"name":"ublock-origin","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ublock-origin@1.22.2+dfsg-1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.19.0+dfsg-2","1.22.2+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"chromium-ublock-origin","binary_version":"1.22.2+dfsg-1"},{"binary_name":"webext-ublock-origin","binary_version":"1.22.2+dfsg-1"},{"binary_name":"xul-ext-ublock-origin","binary_version":"1.22.2+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}},{"package":{"name":"umatrix","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/umatrix@1.3.16+dfsg-2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.16+dfsg-2"],"ecosystem_specific":{"binaries":[{"binary_name":"webext-umatrix","binary_version":"1.3.16+dfsg-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}},{"package":{"name":"ublock-origin","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ublock-origin@1.40.2+dfsg-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.33.0+dfsg-1build1","1.37.0+dfsg-1","1.39.0+dfsg-2","1.40.2+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"webext-ublock-origin","binary_version":"1.40.2+dfsg-1"},{"binary_name":"webext-ublock-origin-chromium","binary_version":"1.40.2+dfsg-1"},{"binary_version":"1.40.2+dfsg-1","binary_name":"webext-ublock-origin-firefox"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}},{"package":{"name":"umatrix","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/umatrix@1.4.0+dfsg-1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.0+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"webext-umatrix","binary_version":"1.4.0+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}},{"package":{"name":"ublock-origin","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ublock-origin@1.55.0+dfsg-1?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.51.0+dfsg-2","1.52.0+dfsg-1","1.53.3rc0+dfsg-1","1.54.0+dfsg-1","1.55.0+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"webext-ublock-origin-chromium","binary_version":"1.55.0+dfsg-1"},{"binary_name":"webext-ublock-origin-firefox","binary_version":"1.55.0+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-36773.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}