Confluence 目录穿越漏洞导致代码执行CVE-2019-3398

Posted 2021-02-17

0x00 漏洞详情

Confluence Server和Data Center产品在downloadallattachments资源中存在一个路径穿越漏洞。有权向页面和（或）博客添加附件，或创建新空间或个人空间，或者对空间具有“管理员”权限的远程***者可以利用此漏洞将文件写入任意位置，最终导致远程代码执行。

0x01 影响范围

0x02 修复建议

升级Confluence Server或Data Center版本：
6.6.13
6.13.4
6.14.3
6.15.2
执行官方缓解措施：
停止Confluence编辑<install-directory>/conf/server.xml
如果你没有为 Confluence 配置 context path，则将以下代码添加至 <Host> 元素中：
<br/>&lt;Context path="/pages/downloadallattachments.action" docBase="" &gt; &lt;Valapp className="org.apache.catalina.valapps.RemoteAddrValapp" deny="*" /&gt; &lt;/Context&gt;

如果你为 Confluence 配置了 context path，比如说 /wiki，则需要将以下代码添加至 <Host> 元素中：
<br/>&lt;Context path="/wiki/pages/downloadallattachments.action" docBase="" &gt; &lt;Valapp className="org.apache.catalina.valapps.RemoteAddrValapp" deny="*" /&gt; &lt;/Context&gt;

0x03 环境搭建

wget https://www.atlassian.com/software/confluence/downloads/binary/atlassian-confluence-6.13.0.zip<br/>unzip atlassian-confluence-6.13.0.zip<br/>cd atlassian-confluence-6.13.0/confluence/WEB-INF/classes<br/>
编辑confluence-init.properties
修改confluence.home

启动：
cd atlassian-confluence-6.13.0/bin
./start-confluence.sh

0x04 漏洞复现

第一步上传文件：

第二步：打包下载（触发漏洞）

第三步：访问shell
http://192.168.56.248:8090/cmd13.jsp?comment=whoami

0x05 漏洞分析

使用idea 进行远程调试
首先需要在catalina.sh 添加如下代码
export JAVA_OPTS=‘-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8002‘<br/>
在idea中配置：

此时可以进行远程调试了
`public String execute() throws Exception {
List<Attachment> latestAttachments = this.attachmentManager.getLatestVersionsOfAttachments(this.getPage());
Iterator var2 = latestAttachments.iterator();

    while(var2.hasNext()) {
        Attachment attachment = (Attachment)var2.next();
        File tmpFile = new File(this.getTempDirectoryForZipping(), attachment.getFileName());
        InputStream inputStream = this.attachmentManager.getAttachmentData(attachment);
        Throwable var6 = null;

        try {
            OutputStream fileOutputStream = new FileOutputStream(tmpFile);
            Throwable var8 = null;

            try {
                ByteStreams.copy(inputStream, fileOutputStream);
            } catch (Throwable var31) {
                var8 = var31;
                throw var31;
            } finally {
                if (fileOutputStream != null) {
                    if (var8 != null) {
                        try {
                            fileOutputStream.close();
                        } catch (Throwable var30) {
                            var8.addSuppressed(var30);
                        }
                    } else {
                        fileOutputStream.close();
                    }
                }

            }
        } catch (Throwable var33) {
            var6 = var33;
            throw var33;
        } finally {
            if (inputStream != null) {
                if (var6 != null) {
                    try {
                        inputStream.close();
                    } catch (Throwable var29) {
                        var6.addSuppressed(var29);
                    }
                } else {
                    inputStream.close();
                }
            }

        }
    }

    File zipFile = new File(this.getConfluenceTempDirectoryPath() + File.separator + this.getZipFilename() + ".zip");
    FileUtils.createZipFile(this.getTempDirectoryForZipping(), zipFile);
    FileUtils.deleteDir(this.getTempDirectoryForZipping());
    this.downloadPath = this.prepareDownloadPath(zipFile.getPath()) + "?contentType=application/zip";
    this.gateKeeper.addKey(this.prepareDownloadPath(zipFile.getPath()), this.getAuthenticatedUser());
    return "success";
}`

漏洞产生在：
ByteStreams.copy(inputStream, fileOutputStream);

跟踪fileOutputStream

attachment有title参数：

attachment.getFileName() 获取的值就是title

title 值来源

<br/>InputStream inStream = this.getStreamForEncoding(this.httpServletRequest);<br/>this.fileUploadManager.storeResource(new InputStreamAttachmentResource(inStream, this.filename, this.mimeType, this.size, (String)null, this.minorEdit), (ContentEntityObject)content);<br/>if (this.withEditorPlaceholder) {<br/>this.jsonResult.put("htmlForEditor", this.dragAndDropService.getAttachmentEditorHtml(this.filename, (ContentEntityObject)content, this.isVFMSupported, this.contentType));<br/>}<br/>
对filename 没有进行任何过滤

0x06 参考链接

https://confluence.atlassian.com/doc/confluence-security-advisory-2019-04-17-968660855.html
https://twitter.com/search?q=CVE-2019-3398&src=typd

https://www.atlassian.com/software/confluence/download-archives?_ga=2.89576473.387035393.1555556487-322510123.1555556487

https://confluence.atlassian.com/conf59/installing-confluence-on-linux-792499834.html