Jeesns Article‘s Comments Store XSS

## Jeesns Article‘s Comments Store XSS ### Introduction to Vulnerability JEESNS is a social management system based on JAVA enterprise-level platform. Based on the advantages of enterprise-level JAVA, such as high efficiency, security and stability, it creates a pioneering domestic Java version of open source SNS. JEESNS can be used to build portals, forums, communities, Weibo, Q&A, knowledge payment platform, etc. In jeesns <= 1.4.2, the article comments on the user's input filtering is incomplete, resulting in a stored XSS vulnerability. ### Vulnerability Impact * Jeesns <= 1.4.2 ### Vulnerability Analysis The data submitted by the user foreground will pass XSSFilter, and the doFilter will call XssWrapper. ```java Package com.lxinet.jeesns.core.utils; Import java.util.regex.Matcher; Import java.util.regex.Pattern; Import javax.servlet.http.HttpServletRequest; Import javax.servlet.http.HttpServletRequestWrapper; Import org.springframework.web.util.HtmlUtils; Public class XssWrapper extends HttpServletRequestWrapper { Private static final String REGEX_SCRIPT = "<script[\\s\\S]*?<\\/script>"; Private static final String REGEX_STYLE = "<style[^>]*?>[\\s\\S]*?<\\/style>"; ...... Public String getParameter(String parameter) { String value = super.getParameter(parameter); Return value == null ? null : this.cleanXSS(value); } Public String getHeader(String name) { String value = super.getHeader(name); Return value == null ? null : this.cleanXSS(value); } Private String cleanXSS(String value) { Value = dealScript(value); Value = dealStyle(value); String[] eventKeywords = new String[]{"onmouseover", "onmouseout", "onmousedown", "onmouseup", "onmousemove", "onclick", "ondblclick", "onkeypress", "onkeydown", "onkeyup", "ondragstart", "onerrorupdate", "onhelp", "onreadystatechange", "onrowenter", "onrowexit", "onselectstart", "onload", "onunload", "onbeforeunload", "onblur", "onerror", "onfocus ", "onresize", "onscroll", "oncontextmenu", "alert"}; For(int i = 0; i < eventKeywords.length; ++i) { Value = value.replaceAll("(?i)" + eventKeywords[i], "_" + eventKeywords[i]); } Return value; } Private static String dealScript(String val) { Pattern p = Pattern.compile("<script[\\s\\S]*?<\\/script>"); Return htmlEscape(p, val); } Private static String dealStyle(String val) { Pattern p = Pattern.compile("<style[^>]*?>[\\s\\S]*?<\\/style>"); Return htmlEscape(p, val); } Private static String htmlEscape(Pattern p, String val) { String s; String newVal; For(Matcher m = p.matcher(val); m.find(); val = val.replace(s, newVal)) { s = m.group(); newVal = HtmlUtils.htmlEscape(s); } Return val; } } ``` As you can see, the `<script>` and `<style>` tags are filtered, and some HTML events are escaped and filtered. However, when matching tags, there is no case processing, which can be bypassed by capitalization. See the `save()` of the function `jeesns-service\src\main\java\com\lxinet\jeesns\service\cms\impl\ArticleCommentServiceImpl.java` where the article comments are saved. ```java @Override Public boolean save(Member loginMember, String content, Integer articleId) { Article article = articleService.findById(articleId); ValidUtill.checkIsNull(article, "Article does not exist"); ValidUtill.checkIsBlank(content, "Content cannot be empty"); ArticleComment articleComment = new ArticleComment(); articleComment.setMemberId(loginMember.getId()); articleComment.setArticleId(articleId); articleComment.setContent(content); Boolean result = super.save(articleComment); If(!result){ Throw new OpeErrorException(); } @@会员处理 and send system messages messageService.atDeal(loginMember.getId(),content, AppTag.CMS, MessageType.CMS_ARTICLE_COMMENT_REFER,articleComment.getId()); messageService.diggDeal(loginMember.getId(), article.getMemberId(), content, AppTag.CMS, MessageType.CMS_ARTICLR_REPLY, article.getId()); //Article review reward scoreDetailService.scoreBonus(loginMember.getId(), ScoreRuleConsts.ARTICLE_REVIEWS, articleComment.getId()); Return true; } ``` The data of the user condition is not further filtered, and is directly saved to the database, and then the front end directly renders, resulting in a storage type XSS. ### Vulnerability recurrence 1. Register a user 2. Fill in the article comments with XSS payload `<Script>prompt(/xss/)</Script>`  3. Trigger XSS when viewing the article.