Jeesns Group Posts Store XSS

## Jeesns Group Posts 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 group postings did not completely filter the user's input, 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\group\impl\GroupTopicServiceImpl.java` that saves the group post. ```java @Override @Transactional Public boolean save(Member member, GroupTopic groupTopic) { If(groupTopic.getGroupId() == null || groupTopic.getGroupId() == 0){ Throw new ParamException(); } Group group = groupService.findById(groupTopic.getGroupId()); ValidUtill.checkIsNull(group, "Group does not exist"); If(groupFansService.findByMemberAndGroup(group.getId(),member.getId()) == null){ Throw new OpeErrorException("You must follow this group to post"); } If(group.getCanPost() == 0){ Throw new OpeErrorException("group has closed post function"); } groupTopic.setMemberId(member.getId()); / / Save the article groupTopic.setStatus(group.getTopicReview()==0?1:0); Int result = groupTopicDao.saveObj(groupTopic); If(result == 1){ @@会员处理 and send system messages messageService.atDeal(member.getId(), groupTopic.getContent(), AppTag.GROUP, MessageType.GROUP_TOPIC_REFER, groupTopic.getId()); //Group posting rewards scoreDetailService.scoreBonus(member.getId(), ScoreRuleConsts.GROUP_POST, groupTopic.getId()); actionLogService.save(member.getCurrLoginIp(), member.getId(), ActionUtil.POST_GROUP_TOPIC,"", ActionLogType.GROUP_TOPIC.getValue(), groupTopic.getId()); } Return result == 1; } ``` 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 at the front desk and follow the group. 2. Post, fill in the XSS payload `<Script>prompt(/xss/)</Script>` at the title.  3. Trigger XSS when viewing group posts.