The two built-in name-finder patterns exposed by
\nopennlp.tools.namefind.RegexNameFinderFactory – DEFAULT_REGEX_NAME_FINDER.EMAIL
\nand DEFAULT_REGEX_NAME_FINDER.URL\u00a0– contain ambiguous nested quantifiers. An
\napplication that obtains these finders through
\nRegexNameFinderFactory.getDefaultRegexNameFinders(…) and then applies them to
\nuntrusted text through RegexNameFinder.find(String[]) or RegexNameFinder.find(String)
\ncan be driven into super-linear backtracking or into unbounded matcher recursion by a
\nsmall crafted input.<\/p>\n
For the EMAIL pattern, a long run of local-part characters that is never followed by an
\n@ forces the matcher to re-scan to end-of-input from every starting offset. Cost grows
\nquadratically with input length: an input of approximately 32 KB consumes several seconds
\nof CPU in a single find() call and returns no match, and each doubling of the input
\nmultiplies the cost roughly four-fold.<\/p>\n
For the URL pattern, the query-string sub-expression nests a capturing repetition inside
\nan outer repetition. The JDK matcher recurses once per query token, so an input of
\napproximately 4 KB containing many &-separated tokens exhausts the thread stack and
\ncauses java.lang.StackOverflowError to propagate out of find(), terminating the
\ncalling thread. On a thread created with a smaller stack (for example -Xss512k, typical
\nof server worker pools) approximately 1 KB is sufficient.<\/p>\n
In both cases an attacker who can supply text for analysis can convert a single request
\ninto seconds to minutes of pinned CPU, or into an abrupt thread death, denying service to
\nthe embedding application. No authentication, special configuration, or model file is
\nrequired beyond the application having selected one of the two built-in finders.<\/p>\n
This issue affects Apache OpenNLP: from 2.0.0 through 2.5.11; from 3.0.0-M1 through
\n3.0.0-M5.<\/p>\n
Users are recommended to upgrade to version 2.5.12, or to 3.0.0-M6 for users tracking the
\n3.0.0 milestone line, which fix the issue.<\/p>\n","protected":false},"excerpt":{"rendered":"
The two built-in name-finder patterns exposed by
\nopennlp.tools.namefind.RegexNameFinderFactory – DEFAULT_REGEX_NAME_FINDER.EMAIL
\nand DEFAULT_REGEX_NAME_FINDER.URL\u00a0– contain ambiguous nested quantifier<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21211","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21211","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}