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.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 6.8 · libexpat_project, python, appleNVD modified 2026-10-14 07:16
Affected (CPE criteria) 7
cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*cpe:2.3:a:python:python:*:*:*:*:*:*:*:*cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
References 50
- http://openwall.com/lists/oss-security/2013/02/22/3 Exploit, Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Oct/61 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Oct/62 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Oct/63 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/33 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/34 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/35 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/38 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/39 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/40 Mailing List, Third Party Advisory
- http://securitytracker.com/id?1028213 Third Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2013/04/12/6 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/4 Mailing List, Third Party Advisory
- http://www.osvdb.org/90634 Broken Link
- http://www.securityfocus.com/bid/58233 Broken Link, Third Party Advisory, VDB Entry
- https://github.com/libexpat/libexpat/blob/R_2_4_1/expat/Changes
- https://lists.apache.org/thread.html/r41eca5f4f09e74436cbb05dec450fc2bef37b5d3e966aa7cc5fada6d%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rfb2c193360436e230b85547e85a41bea0916916f96c501f5b6fc4702%40%3Cusers.openoffice.apache.org%3E
- https://security.gentoo.org/glsa/201701-21 Third Party Advisory
- https://support.apple.com/kb/HT212804 Third Party Advisory
- https://support.apple.com/kb/HT212805 Third Party Advisory
- https://support.apple.com/kb/HT212807 Third Party Advisory
- https://support.apple.com/kb/HT212814 Third Party Advisory
- https://support.apple.com/kb/HT212815 Third Party Advisory
- https://support.apple.com/kb/HT212819 Third Party Advisory
- http://openwall.com/lists/oss-security/2013/02/22/3 Exploit, Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Oct/61 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Oct/62 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Oct/63 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/33 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/34 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/35 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/38 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/39 Mailing List, Third Party Advisory
- http://seclists.org/fulldisclosure/2021/Sep/40 Mailing List, Third Party Advisory
- http://securitytracker.com/id?1028213 Third Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2013/04/12/6 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/4 Mailing List, Third Party Advisory
- http://www.osvdb.org/90634 Broken Link
- http://www.securityfocus.com/bid/58233 Broken Link, Third Party Advisory, VDB Entry
- https://lists.apache.org/thread.html/r41eca5f4f09e74436cbb05dec450fc2bef37b5d3e966aa7cc5fada6d%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rfb2c193360436e230b85547e85a41bea0916916f96c501f5b6fc4702%40%3Cusers.openoffice.apache.org%3E
- https://security.gentoo.org/glsa/201701-21 Third Party Advisory
- https://support.apple.com/kb/HT212804 Third Party Advisory
- https://support.apple.com/kb/HT212805 Third Party Advisory
- https://support.apple.com/kb/HT212807 Third Party Advisory
- https://support.apple.com/kb/HT212814 Third Party Advisory
- https://support.apple.com/kb/HT212815 Third Party Advisory
- https://support.apple.com/kb/HT212819 Third Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html