--- id: CVE-2013-0340 title: >- expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HT… summary: >- expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HT… severity: medium cvss: 6.8 cvssVector: 'AV:N/AC:M/Au:N/C:P/I:P/A:P' cwe: - CWE-611 vendor: libexpat_project product: libexpat affected: - libexpat < 2.4.0 - 'python >= 3.6.0, < 3.6.15' - 'python >= 3.7.0, < 3.7.12' - 'python >= 3.8.0, < 3.8.12' - 'python >= 3.9.0, < 3.9.7' - ipados < 14.8 - iphone_os < 14.8 - macos < 11.6 - tvos < 15.0 - watchos < 8.0 patched: - libexpat 2.4.0 - python 3.9.7 - ipados 14.8 - iphone_os 14.8 - macos 11.6 - tvos 15.0 - watchos 8.0 published: '2014-01-21' updated: '2026-10-14' sourceUpdated: '2026-10-14T07:16:35.810' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2013-0340' references: - url: 'http://openwall.com/lists/oss-security/2013/02/22/3' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Oct/61' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Oct/62' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Oct/63' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Sep/33' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Sep/34' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Sep/35' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Sep/38' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Sep/39' label: secalert@redhat.com - url: 'http://seclists.org/fulldisclosure/2021/Sep/40' label: secalert@redhat.com - url: 'http://securitytracker.com/id?1028213' label: secalert@redhat.com - url: 'http://www.openwall.com/lists/oss-security/2013/04/12/6' label: secalert@redhat.com - url: 'http://www.openwall.com/lists/oss-security/2021/10/07/4' label: secalert@redhat.com - url: 'http://www.osvdb.org/90634' label: secalert@redhat.com - url: 'http://www.securityfocus.com/bid/58233' label: secalert@redhat.com - url: 'https://github.com/libexpat/libexpat/blob/R_2_4_1/expat/Changes' label: secalert@redhat.com - url: >- https://lists.apache.org/thread.html/r41eca5f4f09e74436cbb05dec450fc2bef37b5d3e966aa7cc5fada6d%40%3Cannounce.apache.org%3E label: secalert@redhat.com - url: >- https://lists.apache.org/thread.html/rfb2c193360436e230b85547e85a41bea0916916f96c501f5b6fc4702%40%3Cusers.openoffice.apache.org%3E label: secalert@redhat.com - url: 'https://security.gentoo.org/glsa/201701-21' label: secalert@redhat.com - url: 'https://support.apple.com/kb/HT212804' label: secalert@redhat.com - url: 'https://support.apple.com/kb/HT212805' label: secalert@redhat.com - url: 'https://support.apple.com/kb/HT212807' label: secalert@redhat.com - url: 'https://support.apple.com/kb/HT212814' label: secalert@redhat.com - url: 'https://support.apple.com/kb/HT212815' label: secalert@redhat.com - url: 'https://support.apple.com/kb/HT212819' label: secalert@redhat.com - url: 'http://openwall.com/lists/oss-security/2013/02/22/3' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Oct/61' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Oct/62' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Oct/63' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Sep/33' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Sep/34' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Sep/35' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Sep/38' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Sep/39' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://seclists.org/fulldisclosure/2021/Sep/40' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://securitytracker.com/id?1028213' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.openwall.com/lists/oss-security/2013/04/12/6' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.openwall.com/lists/oss-security/2021/10/07/4' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.osvdb.org/90634' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.securityfocus.com/bid/58233' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/r41eca5f4f09e74436cbb05dec450fc2bef37b5d3e966aa7cc5fada6d%40%3Cannounce.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/rfb2c193360436e230b85547e85a41bea0916916f96c501f5b6fc4702%40%3Cusers.openoffice.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.gentoo.org/glsa/201701-21' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://support.apple.com/kb/HT212804' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://support.apple.com/kb/HT212805' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://support.apple.com/kb/HT212807' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://support.apple.com/kb/HT212814' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://support.apple.com/kb/HT212815' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://support.apple.com/kb/HT212819' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd epss: 0.19433 epssPercentile: 0.97314 ingestedAt: '2026-10-09T21:12:42.312Z' --- ## Overview expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetEntityDeclHandler function, which allows remote attackers to cause a denial of service (resource consumption), send HTTP requests to intranet servers, or read arbitrary files via a crafted XML document, aka an XML External Entity (XXE) issue. NOTE: it could be argued that because expat already provides the ability to disable external entity expansion, the responsibility for resolving this issue lies with application developers; according to this argument, this entry should be REJECTed, and each affected application would need its own CVE. ## Affected - `libexpat < 2.4.0` - `python >= 3.6.0, < 3.6.15` - `python >= 3.7.0, < 3.7.12` - `python >= 3.8.0, < 3.8.12` - `python >= 3.9.0, < 3.9.7` - `ipados < 14.8` - `iphone_os < 14.8` - `macos < 11.6` - `tvos < 15.0` - `watchos < 8.0` ## Remediation Upgrade past the affected range: - `libexpat 2.4.0` - `python 3.9.7` - `ipados 14.8` - `iphone_os 14.8` - `macos 11.6` - `tvos 15.0` - `watchos 8.0`