disable external entity resolution in log4j 1.x XmlConfiguration - #4198
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jmestwa-coder wants to merge 1 commit into
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disable external entity resolution in log4j 1.x XmlConfiguration#4198jmestwa-coder wants to merge 1 commit into
jmestwa-coder wants to merge 1 commit into
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@jmestwa-coder Thanks for the PR! I appreciate your patience. I'll try to get it closed ASAP. |
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The Log4j 1.x
XmlConfigurationreader resolves external XML entities.DocumentBuilderFactoryis built withsetValidating(true)and no entity restrictionsLog4jEntityResolveronly handleslog4j.dtdand returnsnullotherwise, so the parser falls back to fetching external entitieslog4j.xmlwith aSYSTEMentity can read local files or reach network URLsdisableDtdProcessinghardening already inlog4j-core'sXmlConfigurationTest loads a config with an external entity and asserts it is not resolved.
Checklist
2.xbranch./mvnw verifysucceedssrc/changelog/.2.x.xdirectory