XML Entity Expansion Denial of Service Vulnerability in Apache Tika 1.19 (CVE-2018-11761)

CVE-2018-11796 · MEDIUM Severity

AV:N/AC:L/AU:N/C:N/I:N/A:P

In Apache Tika 1.19 (CVE-2018-11761), we added an entity expansion limit for XML parsing. However, Tika reuses SAXParsers and calls reset() after each parse, which, for Xerces2 parsers, as per the documentation, removes the user-specified SecurityManager and thus removes entity expansion limits after the first parse. Apache Tika versions from 0.1 to 1.19 are therefore still vulnerable to entity expansions which can lead to a denial of service attack. Users should upgrade to 1.19.1 or later.

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