{"id":"CVE-2021-32807","aliases":["EUVD-2021-0001","GHSA-qcx9-j53g-ccgf","PYSEC-2021-335","PYSEC-2021-875"],"status":"published","title":"Remote Code Execution via unsafe classes in otherwise permitted modules","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","severity":{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.02107,"percentile":0.81997,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1321","CWE-915"],"published":"2021-07-30T21:20:11Z","modified":"2026-10-20T10:54:43Z","fixes":[{"ecosystem":"PyPI","package":"accesscontrol","fixed_in":["4.3","5.2"],"sources":["ghsa","osv"]},{"ecosystem":"PyPI","package":"zope","fixed_in":["4.3","5.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"accesscontrol","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0"},{"fixed":"4.3"}]}]},{"source":"ghsa","ecosystem":"PyPI","package":"accesscontrol","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0"},{"fixed":"5.2"}]}]},{"source":"ghsa","ecosystem":"PyPI","package":"zope","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0"},{"fixed":"4.3"}]}]},{"source":"ghsa","ecosystem":"PyPI","package":"zope","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0"},{"fixed":"5.2"}]}]},{"source":"osv","ecosystem":"PyPI","package":"accesscontrol","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0"},{"fixed":"4.3"}]}],"versions":["4.0","4.1","4.2"]},{"source":"osv","ecosystem":"PyPI","package":"accesscontrol","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0"},{"fixed":"5.2"}]}],"versions":["5.0","5.1"]},{"source":"osv","ecosystem":"PyPI","package":"zope","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0"},{"fixed":"4.3"}]}],"versions":["4.0","4.1","4.1.1","4.1.2","4.1.3","4.2","4.2.1"]},{"source":"osv","ecosystem":"PyPI","package":"zope","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0"},{"fixed":"5.2"}]}],"versions":["5.0","5.1","5.1.1","5.1.2"]},{"source":"osv","ecosystem":"PyPI","package":"accesscontrol","ranges":[{"type":"GIT","events":[{"introduced":"0"},{"fixed":"b42dd4badf803bb9fb71ac34cd9cb0c249262f2c"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.0"},{"fixed":"4.3"},{"introduced":"5.0"},{"fixed":"5.2"}]}],"versions":["4.0","4.1","4.2","5.0","5.1"]},{"source":"osv","ecosystem":"PyPI","package":"zope","ranges":[{"type":"GIT","events":[{"introduced":"0"},{"fixed":"b42dd4badf803bb9fb71ac34cd9cb0c249262f2c"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.0"},{"fixed":"4.3"},{"introduced":"5.0"},{"fixed":"5.2"}]}],"versions":["4.0","4.1","4.1.1","4.1.2","4.1.3","4.2","4.2.1","5.0","5.1","5.1.1","5.1.2","4.0b7","4.0b6","4.0b5","4.0b4","4.0b3","4.0b2","4.0b1","4.0a7","4.0a6","4.0a5","3.0.12","4.0a3","4.0a2","4.0a1","3.0.11","3.0.10","3.0.9","3.0.8","3.0.7"]}],"products":[{"vendor":"zope","product":"accesscontrol"},{"vendor":"zopefoundation","product":"accesscontrol"}],"references":[{"url":"https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgf","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/zopefoundation/AccessControl/commit/b42dd4badf803bb9fb71ac34cd9cb0c249262f2c","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://github.com/zopefoundation/AccessControl/blob/master/CHANGES.rst#51-2021-07-30","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-32807","tags":["advisory"]},{"url":"https://github.com/zopefoundation/Zope/security/advisories/GHSA-g4gq-j4p2-j8fr","tags":["web"]},{"url":"https://github.com/zopefoundation/AccessControl/commit/ae2dab0cc34e6dd1561c5b12d4a56cd140f87e1d","tags":["web"]},{"url":"https://github.com/zopefoundation/Zope/commit/869f947e586517566509e0ccdd4d99b60704cc02","tags":["web"]},{"url":"https://github.com/zopefoundation/Zope/commit/f72a18dda8e9bf2aedb46168761668464a4be988","tags":["web"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/accesscontrol/PYSEC-2021-335.yaml","tags":["web"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/accesscontrol/PYSEC-2021-370.yaml","tags":["web"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/zope/PYSEC-2021-368.yaml","tags":["web"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/zope/PYSEC-2021-875.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-qcx9-j53g-ccgf"},{"url":"https://github.com/zopefoundation/AccessControl","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-32807","title":"Remote Code Execution via unsafe classes in otherwise permitted modules","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","status":"published","published":"2021-07-30T21:20:11Z","modified":"2024-08-03T23:33:55.893Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-915"],"updated_at":"2026-11-02T14:33:07.014772Z"}],"euvd":[{"id":"EUVD-2021-0001","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","status":"published","published":"2021-07-30T21:20:11Z","modified":"2024-08-03T23:33:55Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"updated_at":"2026-11-03T03:24:35.855495Z"}],"ghsa":[{"id":"GHSA-qcx9-j53g-ccgf","title":"Remote Code Execution via unsafe classes in otherwise permitted modules","description":"### Impact\nThe module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. \n\nThe policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution.\n\nBy default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk.\n\n### Patches\nThe problem has been fixed in AccessControl 4.3 and 5.2.\nOnly AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7.\n\n### Workarounds\nA site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [AccessControl issue tracker](https://github.com/zopefoundation/AccessControl/issues)\n* Email us at [security@plone.org](mailto:security@plone.org)","status":"published","published":"2021-08-05T17:01:30Z","modified":"2026-06-09T13:03:01Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium"},{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-915","CWE-1321"],"updated_at":"2026-11-02T14:40:24.856614Z"}],"nvd":[{"id":"CVE-2021-32807","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","status":"published","published":"2021-07-30T22:15:07.967Z","modified":"2026-06-17T03:53:40.153Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.5,"vector":"AV:N/AC:L/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-915","CWE-1321"],"updated_at":"2026-11-02T14:06:56.185362Z"}],"osv":[{"id":"CVE-2021-32807","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","status":"published","published":"2021-07-30T22:15:07.967Z","modified":"2026-10-20T10:54:43.141805677Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:19.793849Z"},{"id":"GHSA-qcx9-j53g-ccgf","title":"Remote Code Execution via unsafe classes in otherwise permitted modules","description":"### Impact\nThe module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. \n\nThe policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution.\n\nBy default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk.\n\n### Patches\nThe problem has been fixed in AccessControl 4.3 and 5.2.\nOnly AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7.\n\n### Workarounds\nA site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [AccessControl issue tracker](https://github.com/zopefoundation/AccessControl/issues)\n* Email us at [security@plone.org](mailto:security@plone.org)","status":"published","published":"2021-08-05T17:01:30Z","modified":"2026-07-09T16:56:14.762787976Z","cvss":[{"version":"3.1","score":4.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium"},{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-1321","CWE-915"],"updated_at":"2026-11-02T15:46:54.40888Z"},{"id":"PYSEC-2021-335","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","status":"published","published":"2021-07-30T22:15:00Z","modified":"2026-07-09T16:56:14.762787976Z","updated_at":"2026-11-02T15:52:52.682031Z"},{"id":"PYSEC-2021-875","description":"The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk. The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, a site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.","status":"published","published":"2021-07-30T22:15:00Z","modified":"2026-07-09T16:56:14.762787976Z","updated_at":"2026-11-02T15:52:53.449407Z"}]}}