Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

Tenable 部落格

訂閱

CVE-2020-1938: Ghostcat - Apache Tomcat AJP File Read/Inclusion Vulnerability (CNVD-2020-10487)

Several proof-of-concept exploit scripts for recently patched flaw in Apache Tomcat are now available.

背景說明

On February 20, China National Vulnerability Database (CNVD) published a security advisory for CNVD-2020-10487, a severe vulnerability in Apache Tomcat’s Apache JServ Protocol (or AJP). AJP is a binary protocol designed to handle requests sent to a web server destined for an application server in order to improve performance.


Ghostcat logo created by Chaitin Tech

The vulnerability, dubbed Ghostcat, was discovered by researchers at Chaitin Tech and reported to the Apache Software Foundation on January 3, 2020.

分析

CVE-2020-1938 is a file read/inclusion vulnerability in the AJP connector in Apache Tomcat. This is enabled by default with a default configuration port of 8009. A remote, unauthenticated attacker could exploit this vulnerability to read web application files from a vulnerable server. In instances where the vulnerable server allows file uploads, an attacker could upload malicious JavaServer Pages (JSP) code within a variety of file types and trigger this vulnerability to gain remote code execution (RCE).

Because AJP is enabled by default in the /conf/server.xml file in Apache Tomcat 6, 7, 8 and 9, all unpatched versions of Tomcat are vulnerable to Ghostcat.

Research community investigates

Henry Chen, a security researcher at Alibaba Cloud, published a tweet confirming that exploiting the vulnerability would allow someone to “read any webapps files or include a file to RCE.” Chen shared a GIF showing the successful exploitation of the vulnerability.

Another security researcher, Joao Matos, confirmed that RCE is possible in cases where uploading files is a “feature,” that the uploaded files are “saved inside the document root,” and the AJP port can be reached directly.

Potential impact

According to a post in the Apache Software Foundation Blog from 2010, Apache Tomcat has been downloaded over 10 million times. Apache Tomcat is used by a variety of software applications, often bundled as an embedded web server. The potential impact of this vulnerability is wide, though we do not have the complete picture as of yet. As this information is still fresh, we anticipate additional details about its impact will become public in the coming weeks and months.

概念驗證

Since the security advisory was published, several researchers have shared proof-of-concept exploit scripts [1, 2, 3, 4, 5] to GitHub.

解決方法

Patch availability

Apache has released patches for several versions of Tomcat.

Apache VersionAffected Release VersionsFixed Version
Apache Tomcat 99.0.30 and below9.0.31
Apache Tomcat 88.5.50 and below8.5.51
Apache Tomcat 77.0.99 and below7.0.100

This vulnerability also reportedly affects Apache Tomcat 6, but Apache has not released a patch, as it is likely no longer supported. Users are strongly encouraged to upgrade to a newer version of Tomcat to ensure they’re protected against this vulnerability.

緩和風險措施

If patching is not feasible at this time, there are a few mitigation steps suggested by Chaitin Tech that can be taken to prevent exploitation of this vulnerability, since the AJP Connector is enabled by default.

If your site is not actively using the AJP Connector, simply comment it out from the /conf/server.xml file:

However, if you are using the AJP Connector on your site, you’ll need to ensure the AJP Connector contains the requiredSecret attribute, which is akin to a password, so it needs to be strong and unique.

UPDATE 02/23/2020: The above section has been updated to reference the correct attribute, requiredSecret.

找出受影響的系統

A list of Tenable plugins to identify this vulnerability will appear here as they’re released.

取得更多資訊

加入 Tenable Community 上的 Tenable 安全應變團隊

深入瞭解Tenable,這是用於全面管理現代攻擊破綻首創的網路曝險平台。

Get a free 30-day trial of Tenable.io Vulnerability Management.

相關文章

您可以使用的網路安全最新消息

輸入您的電子郵件,就不會錯過來自 Tenable 專家提供的及時警示與安全指引。

Tenable Vulnerability Management

享受現代、雲端型的弱點管理平台,能夠以無與倫比的準確性查看和追蹤所有資產。

您的 Tenable Vulnerability Management 試用版軟體也包含 Tenable Lumin 和 Tenable Web App Scanning。

Tenable Vulnerability Management

享受現代、雲端型的弱點管理平台,使您能夠以無與倫比的準確性查看和追蹤所有資產。 立即訂閱一年。

100 項資產

選取您的訂閱選項:

立即購買

Tenable Vulnerability Management

享受現代、雲端型的弱點管理平台,能夠以無與倫比的準確性查看和追蹤所有資產。

您的 Tenable Vulnerability Management 試用版軟體也包含 Tenable Lumin 和 Tenable Web App Scanning。

Tenable Vulnerability Management

享受現代、雲端型的弱點管理平台,使您能夠以無與倫比的準確性查看和追蹤所有資產。 立即訂閱一年。

100 項資產

選取您的訂閱選項:

立即購買

Tenable Vulnerability Management

享受現代、雲端型的弱點管理平台,能夠以無與倫比的準確性查看和追蹤所有資產。

您的 Tenable Vulnerability Management 試用版軟體也包含 Tenable Lumin 和 Tenable Web App Scanning。

Tenable Vulnerability Management

享受現代、雲端型的弱點管理平台,使您能夠以無與倫比的準確性查看和追蹤所有資產。 立即訂閱一年。

100 項資產

選取您的訂閱選項:

立即購買

試用 Tenable Web App Scanning

享受完整存取我們專為新型應用程式所設計、屬於 Tenable One 曝險管理平台一部分的最新 Web 應用程式掃描產品。不需耗費大量人力或中斷重要 Web 應用程式,即可高度準確且安全地掃描您整個線上產品系列中是否含有任何弱點。 立即註冊。

您的 Tenable Web App Scanning 試用版軟體也包含 Tenable Vulnerability Management 和 Tenable Lumin。

購買 Tenable Web App Scanning

享受現代、雲端型的弱點管理平台,使您能夠以無與倫比的準確性查看和追蹤所有資產。 立即訂閱一年。

5 個 FQDN

$3,578

立即購買

試用 Tenable Lumin

利用 Tenable Lumin 視覺化並探索您的曝險管理、追蹤經過一段時間後風險降低的情形以及與同業進行指標分析。

您的 Tenable Lumin 試用版軟體也包含 Tenable Vulnerability Management 和 Tenable Web App Scanning。

購買 Tenable Lumin

聯絡業務代表,瞭解 Tenable Lumin 如何協助您取得您整個環境的深入解析和管理網路風險。

免費試用 Tenable Nessus Professional

免費試用 7 天

Tenable Nessus 是目前市場上最全方位的弱點掃描器。

最新 - Tenable Nessus Expert
現已上市

Nessus Expert 新增了更多功能,包括外部攻擊破綻掃描和新增網域及掃描雲端基礎架構的能力。按這裡試用 Nessus Expert。

請填妥以下表單以繼續 Nessus Pro 試用。

購買 Tenable Nessus Professional

Tenable Nessus 是目前市場上最全方位的弱點掃描器。Tenable Nessus Professional 可協助將弱點掃描流程自動化,節省您執行合規工作的時間並讓您與 IT 團隊合作。

購買多年期授權,節省更多。新增 365 天全年無休 24 小時全天候可使用電話、社群及對談的進階支援。

選擇您的授權

購買多年期授權,節省更多。

增加支援與訓練

免費試用 Tenable Nessus Expert

免費試用 7 天

Nessus Expert 是專為現代攻擊破綻所打造,它能讓您從 IT 到雲端洞察更多資訊,並保護貴公司免於弱點危害。

您已經有 Tenable Nessus Professional 了嗎?
升級至 Nessus Expert,免費試用 7 天。

購買 Tenable Nessus Expert

Nessus Expert 是專為現代攻擊破綻所打造,它能讓您從 IT 到雲端洞察更多資訊,並保護貴公司免於弱點危害。

選擇您的授權

購買多年期授權省更多!

增加支援與訓練