{"id":"CVE-2021-20213","aliases":["ALPINE-CVE-2021-20213","DEBIAN-CVE-2021-20213","DLA-2548-1","EUVD-2021-7656","GHSA-gwg6-gwm3-3g4w","UBUNTU-CVE-2021-20213","USN-4886-1"],"status":"published","title":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could...","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.01571,"percentile":0.75713,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-476"],"published":"2021-02-03T00:00:00Z","modified":"2026-10-23T18:03:58Z","fixes":[{"ecosystem":"Alpine:v3.12","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.13","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.14","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.15","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.16","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.17","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.18","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.19","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.20","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.21","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.22","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.23","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"privoxy","fixed_in":["3.0.29-r0"],"sources":["osv"]},{"ecosystem":"Debian:12","package":"privoxy","fixed_in":["3.0.29-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"privoxy","fixed_in":["3.0.29-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"privoxy","fixed_in":["3.0.29-1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:14.04:LTS","package":"privoxy","fixed_in":["3.0.21-7+deb8u1ubuntu0.1~esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:16.04:LTS","package":"privoxy","fixed_in":["3.0.24-1ubuntu0.1"],"sources":["osv"]},{"ecosystem":"Ubuntu:18.04:LTS","package":"privoxy","fixed_in":["3.0.26-5ubuntu0.1"],"sources":["osv"]},{"ecosystem":"Ubuntu:20.04:LTS","package":"privoxy","fixed_in":["3.0.28-2ubuntu0.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.12","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.13","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.14","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.15","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.16","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.17","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.18","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.19","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.20","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.21","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.22","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-r0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.29-1"}]}]},{"source":"osv","ecosystem":"Debian:9","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.26-3+deb9u1"}]}],"versions":["3.0.26-3"],"bundled":9},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.21-7+deb8u1ubuntu0.1~esm1"}]}],"versions":["3.0.21-1","3.0.21-2","3.0.21-7+deb8u1build0.14.04.1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.24-1ubuntu0.1"}]}],"versions":["3.0.23-3","3.0.23-4","3.0.23-5","3.0.24-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.26-5ubuntu0.1"}]}],"versions":["3.0.26-3","3.0.26-4","3.0.26-5"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.28-2ubuntu0.1"}]}],"versions":["3.0.28-2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.21-7+deb8u1ubuntu0.1~esm1"}]}],"versions":["3.0.21-1","3.0.21-2","3.0.21-7+deb8u1build0.14.04.1"],"bundled":14},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.24-1ubuntu0.1"}]}],"versions":["3.0.23-3","3.0.23-4","3.0.23-5","3.0.24-1"],"bundled":14},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.26-5ubuntu0.1"}]}],"versions":["3.0.26-3","3.0.26-4","3.0.26-5"],"bundled":14},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"privoxy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.28-2ubuntu0.1"}]}],"versions":["3.0.28-2"],"bundled":14}],"products":[{"vendor":"privoxy","product":"privoxy"}],"references":[{"url":"https://www.privoxy.org/3.0.29/user-manual/whatsnew.html","tags":["x_refsource_MISC","x_transferred","Release Notes","Vendor Advisory","advisory"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1928739","tags":["x_refsource_MISC","x_transferred","Issue Tracking","Patch","Third Party Advisory","fix"]},{"url":"https://security.gentoo.org/glsa/202107-16","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20213"},{"url":"https://github.com/advisories/GHSA-gwg6-gwm3-3g4w"},{"url":"https://security.alpinelinux.org/vuln/CVE-2021-20213","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-20213","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-20213","tags":["report"]},{"url":"https://www.openwall.com/lists/oss-security/2021/02/03/3","tags":["report"]},{"url":"https://www.privoxy.org/gitweb/?p=privoxy.git;a=commit;h=7530132349","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-4886-1","tags":["advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-20213","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2020-35502","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20209","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20210","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20211","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20212","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20214","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20215","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20216","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20217","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20272","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20273","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20275","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-20276","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-20213","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-03-25T18:57:26Z","modified":"2024-08-03T17:30:07.645Z","cwes":["CWE-476"],"updated_at":"2026-11-02T14:32:55.19484Z"}],"euvd":[{"id":"EUVD-2021-7656","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-03-25T18:57:26Z","modified":"2024-08-03T17:30:07Z","updated_at":"2026-11-03T03:25:09.355483Z"}],"ghsa":[{"id":"GHSA-gwg6-gwm3-3g4w","title":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could...","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2022-05-24T17:45:22Z","modified":"2023-01-29T05:06:58Z","cwes":["CWE-476"],"updated_at":"2026-11-02T14:46:07.768849Z"}],"nvd":[{"id":"CVE-2021-20213","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-03-25T19:15:12.97Z","modified":"2026-06-17T03:33:28.933Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:06:51.197859Z"}],"osv":[{"id":"ALPINE-CVE-2021-20213","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-03-25T19:15:12.97Z","modified":"2026-10-23T17:17:56.138992828Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:27:48.646074Z"},{"id":"CVE-2021-20213","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-03-25T19:15:12.97Z","modified":"2026-03-14T01:31:29.587929Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:17.663289Z"},{"id":"DEBIAN-CVE-2021-20213","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-03-25T19:15:12.97Z","modified":"2026-10-23T18:03:58.639101179Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:34.311861Z"},{"id":"UBUNTU-CVE-2021-20213","description":"A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.","status":"published","published":"2021-02-03T00:00:00Z","modified":"2026-02-04T02:21:52.014994Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:25.728622Z"},{"id":"DLA-2548-1","title":"privoxy - security update","status":"published","published":"2021-02-07T00:00:00Z","modified":"2026-03-09T01:22:50.520273Z","updated_at":"2026-11-02T15:46:10.712745Z"},{"id":"USN-4886-1","title":"privoxy vulnerabilities","description":"It was discovered that Privoxy incorrectly handled CGI requests. An attacker\ncould possibly use this issue to cause a denial of service or obtain sensitive\ninformation. (CVE-2020-35502, CVE-2021-20209, CVE-2021-20210,\nCVE-2021-20213, CVE-2021-20215, CVE-2021-20216, CVE-2021-20217,\nCVE-2021-20272, CVE-2021-20273, CVE-2021-20275)\n\nIt was discovered that Privoxy incorrectly handled certain regular\nexpressions. An attacker could possibly use this issue to cause a denial of\nservice or obtain sensitive information. (CVE-2021-20212, CVE-2021-20276)\n\nIt was discovered that Privoxy incorrectly handled client tags. An attacker\ncould possibly use this issue to cause Privoxy to consume resources, resulting\nin a denial of service. This issue only affected Ubuntu 18.04 LTS,\nUbuntu 20.04 LTS and Ubuntu 20.10. (CVE-2021-20211)\n\nIt was discovered that Privoxy incorrectly handled client tags. An attacker\ncould possibly use this issue to cause Privoxy to consume resources, resulting\nin a denial of service. This issue only affected Ubuntu 20.04 LTS and\nUbuntu 20.10. (CVE-2021-20214)\n","status":"published","published":"2021-03-22T16:55:19Z","modified":"2026-06-29T13:48:17.434738418Z","updated_at":"2026-11-02T16:58:15.159055Z"}]}}