{"id":"CVE-2021-41146","aliases":["EUVD-2021-0220","GHSA-vw27-fwjf-5qxm","PYSEC-2021-382"],"status":"published","title":"Arbitrary command execution on Windows in qutebrowser","description":"qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01496,"percentile":0.74528,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-641","CWE-77","CWE-88"],"published":"2021-10-21T17:35:10Z","modified":"2026-10-20T10:54:57Z","fixes":[{"ecosystem":"PyPI","package":"qutebrowser","fixed_in":["2.4.0","1.8.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"qutebrowser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.7.0"},{"fixed":"2.4.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"qutebrowser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.7.0"},{"fixed":"2.4.0"}]}],"versions":["1.10.0","1.10.1","1.10.2","1.11.0","1.11.1","1.12.0","1.13.0","1.13.1","1.14.0","1.14.1","1.7.0","1.8.0","1.8.1","1.8.2","1.8.3","1.9.0","2.0.0","2.0.1","2.0.2","2.1.0","2.1.1","2.2.0","2.2.1","2.2.2","2.2.3","2.3.0","2.3.1"]},{"source":"osv","ecosystem":"PyPI","package":"qutebrowser","ranges":[{"type":"GIT","events":[{"introduced":"0"},{"fixed":"8f46ba3f6dc7b18375f7aa63c48a1fe461190430"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.0"},{"introduced":"2.0.0"},{"fixed":"2.4.0"}]}],"versions":["0.0.0","0.1.0","0.1.1","0.1.2","0.1.3","0.1.4","0.10.0","0.10.1","0.11.0","0.11.1","0.2.0","0.2.1","0.3.0","0.4.0","0.4.1","0.5.0","0.5.1","0.6.0","0.6.1","0.6.2","0.7.0","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.9.0","0.9.1","1.0.0","1.0.1","1.0.2","1.0.3","1.0.4","1.1.0","1.1.1","1.1.2","1.2.0","1.2.1","1.3.0","1.3.1","1.3.2","1.3.3","1.4.0","1.4.1","1.4.2","1.5.0","1.5.1","1.5.2","1.6.0","1.6.1","1.6.2","1.6.3","1.7.0","2.0.0","2.0.1","2.0.2","2.1.0","2.1.1","2.2.0","2.2.1","2.2.2","2.2.3","2.3.0","2.3.1"]}],"products":[{"vendor":"qutebrowser","product":"qutebrowser"}],"references":[{"url":"https://github.com/qutebrowser/qutebrowser/security/advisories/GHSA-vw27-fwjf-5qxm","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/qutebrowser/qutebrowser/commit/8f46ba3f6dc7b18375f7aa63c48a1fe461190430","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41146","tags":["advisory"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/qutebrowser/PYSEC-2021-382.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-vw27-fwjf-5qxm"},{"url":"https://github.com/qutebrowser/qutebrowser","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-41146","title":"Arbitrary command execution on Windows in qutebrowser","description":"qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.","status":"published","published":"2021-10-21T17:35:10Z","modified":"2024-08-04T02:59:31.423Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-77","CWE-88","CWE-641"],"updated_at":"2026-11-02T14:32:59.105382Z"}],"euvd":[{"id":"EUVD-2021-0220","description":"qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.","status":"published","published":"2021-10-21T17:35:10Z","modified":"2024-08-04T02:59:31Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T03:24:19.242491Z"}],"ghsa":[{"id":"GHSA-vw27-fwjf-5qxm","title":"Arbitrary command execution on Windows via qutebrowserurl: URL handler","description":"### Impact\nStarting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers it as a handler for certain URL schemes. With some applications such as Outlook Desktop, opening a specially crafted URL can lead to argument injection, allowing execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`.\n\nOnly Windows installs where qutebrowser is registered as URL handler are affected. It does *not* have to be set as default browser for the exploit to work.\n\n### Patches\nThe issue has been fixed in [qutebrowser v2.4.0](https://github.com/qutebrowser/qutebrowser/releases/tag/v2.4.0) in commit 8f46ba3f6dc7b18375f7aa63c48a1fe461190430.\n\nThe fix also adds additional hardening for potential similar issues on Linux (by adding the new `--untrusted-args` flag to the `.desktop` file), though no such vulnerabilities are known.\n\nBackported patches for older versions are available, but no further releases are planned:\n\n- v1.7.x: d1ceaab\n- v1.8.x: ca7155d\n- v1.9.x: 157d871\n- v1.10.x: 94a6125\n- v1.11.x: 10acfbb\n- v1.12.x: 363a18f\n- v1.13.x: 410f262\n- v1.14.x: e4f4d93\n- v2.0.x: 15a1654\n- v2.1.x: 509ddf2\n- v2.2.x: 03dcba5\n- v2.3.x: 00a694c\n\n(commits are referring to qutebrowser/qutebrowser on GitHub)\n\n### Workarounds\nRemove qutebrowser from the default browser settings entirely, so that it does not handle any kind of URLs. Make sure to remove *all* handlers, including an (accidental) `qutebrowserURL` handler, e.g. using [NirSoft URLProtocolView](https://www.nirsoft.net/utils/url_protocol_view.html).\n\n### Timeline\n2021-10-15: Issue reported via security@qutebrowser.org by Ping Fan (Zetta) Ke of [Valkyrie-X Security Research Group (VXRL)](https://www.vxrl.hk/)\n2021-10-15: Issue confirmed by @The-Compiler (lead developer), author of installer (@bitraid) contacted for help/review\n2021-10-15: CVE assigned by GitHub\n2021-10-15 to 2021-10-17: Fix developed\n2021-10-17: Additional core developer (@toofar) contacted for help/review\n2021-10-21: v2.4.0 released containing the fix\n2021-10-21: Advisory and fix published\n\n### References\nSee the [commit message](https://github.com/qutebrowser/qutebrowser/commit/8f46ba3f6dc7b18375f7aa63c48a1fe461190430) for additional information and references to various similar issues in other projects.\n\n### Acknowledgements\nThanks to Ping Fan (Zetta) Ke of [Valkyrie-X Security Research Group](https://www.vxrl.hk/) (VXRL/@vxresearch) for finding and responsibly disclosing this issue.\n\n### Contact\nIf you have any questions or comments about this advisory, please email [security@qutebrowser.org](mailto:security@qutebrowser.org).","status":"published","published":"2021-10-22T16:20:10Z","modified":"2024-10-16T20:48:14Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-77","CWE-88","CWE-641"],"updated_at":"2026-11-02T14:38:11.479492Z"}],"nvd":[{"id":"CVE-2021-41146","description":"qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.","status":"published","published":"2021-10-21T18:15:10.303Z","modified":"2026-06-17T04:07:58.013Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-77","CWE-88","CWE-641"],"updated_at":"2026-11-02T14:07:00.137719Z"}],"osv":[{"id":"CVE-2021-41146","description":"qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.","status":"published","published":"2021-10-21T18:15:10.303Z","modified":"2026-10-20T10:54:57.413897746Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:21.249056Z"},{"id":"GHSA-vw27-fwjf-5qxm","title":"Arbitrary command execution on Windows via qutebrowserurl: URL handler","description":"### Impact\nStarting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers it as a handler for certain URL schemes. With some applications such as Outlook Desktop, opening a specially crafted URL can lead to argument injection, allowing execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`.\n\nOnly Windows installs where qutebrowser is registered as URL handler are affected. It does *not* have to be set as default browser for the exploit to work.\n\n### Patches\nThe issue has been fixed in [qutebrowser v2.4.0](https://github.com/qutebrowser/qutebrowser/releases/tag/v2.4.0) in commit 8f46ba3f6dc7b18375f7aa63c48a1fe461190430.\n\nThe fix also adds additional hardening for potential similar issues on Linux (by adding the new `--untrusted-args` flag to the `.desktop` file), though no such vulnerabilities are known.\n\nBackported patches for older versions are available, but no further releases are planned:\n\n- v1.7.x: d1ceaab\n- v1.8.x: ca7155d\n- v1.9.x: 157d871\n- v1.10.x: 94a6125\n- v1.11.x: 10acfbb\n- v1.12.x: 363a18f\n- v1.13.x: 410f262\n- v1.14.x: e4f4d93\n- v2.0.x: 15a1654\n- v2.1.x: 509ddf2\n- v2.2.x: 03dcba5\n- v2.3.x: 00a694c\n\n(commits are referring to qutebrowser/qutebrowser on GitHub)\n\n### Workarounds\nRemove qutebrowser from the default browser settings entirely, so that it does not handle any kind of URLs. Make sure to remove *all* handlers, including an (accidental) `qutebrowserURL` handler, e.g. using [NirSoft URLProtocolView](https://www.nirsoft.net/utils/url_protocol_view.html).\n\n### Timeline\n2021-10-15: Issue reported via security@qutebrowser.org by Ping Fan (Zetta) Ke of [Valkyrie-X Security Research Group (VXRL)](https://www.vxrl.hk/)\n2021-10-15: Issue confirmed by @The-Compiler (lead developer), author of installer (@bitraid) contacted for help/review\n2021-10-15: CVE assigned by GitHub\n2021-10-15 to 2021-10-17: Fix developed\n2021-10-17: Additional core developer (@toofar) contacted for help/review\n2021-10-21: v2.4.0 released containing the fix\n2021-10-21: Advisory and fix published\n\n### References\nSee the [commit message](https://github.com/qutebrowser/qutebrowser/commit/8f46ba3f6dc7b18375f7aa63c48a1fe461190430) for additional information and references to various similar issues in other projects.\n\n### Acknowledgements\nThanks to Ping Fan (Zetta) Ke of [Valkyrie-X Security Research Group](https://www.vxrl.hk/) (VXRL/@vxresearch) for finding and responsibly disclosing this issue.\n\n### Contact\nIf you have any questions or comments about this advisory, please email [security@qutebrowser.org](mailto:security@qutebrowser.org).","status":"published","published":"2021-10-22T16:20:10Z","modified":"2026-07-08T06:28:00.918975591Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-641","CWE-77","CWE-88"],"updated_at":"2026-11-02T15:46:57.694388Z"},{"id":"PYSEC-2021-382","description":"qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.","status":"published","published":"2021-10-21T18:15:00Z","modified":"2023-11-08T04:06:52.852418Z","updated_at":"2026-11-02T15:52:52.682031Z"}]}}