CVE-2021-43818— HTML Cleaner allows crafted and SVG embedded scripts to pass through
Quick assessment
Affected
lxml lxml
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
lxml是lxml个人开发者的一个可与Python交互用于定位Html中元素的软件。 lxml 4.6.5之前版本存在注入漏洞，该漏洞源于HTML Cleaner允许某些精心制作的脚本内容以及使用数据URI嵌入的SVG文件中的脚本内容通过。
Possible ATT&CK Techniques 1 AI
T1059 · Command and Scripting Interpreter
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I. Basic Information for CVE-2021-43818
Vulnerability Information
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Vulnerability Title
HTML Cleaner allows crafted and SVG embedded scripts to pass through
Source: CVE Program / CVE List V5
Vulnerability Description
lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.html lets certain crafted script content pass through, as well as script content in SVG files embedded using data URIs. Users that employ the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch. There are no known workarounds available.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
输出中的特殊元素转义处理不恰当(注入)
Source: CVE Program / CVE List V5
Vulnerability Title
lxml 注入漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
lxml是lxml个人开发者的一个可与Python交互用于定位Html中元素的软件。 lxml 4.6.5之前版本存在注入漏洞，该漏洞源于HTML Cleaner允许某些精心制作的脚本内容以及使用数据URI嵌入的SVG文件中的脚本内容通过。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2021-43818
| # | POC Description | Source Link | Shenlong Link |
|---|
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Patches & Fixes for CVE-2021-43818 (3)
Vendor Advisories for CVE-2021-43818 (6)
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https://security.netapp.com/advisory/ntap-20220107-0005/ x_refsource_CONFIRM
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https://github.com/lxml/lxml/security/advisories/GHSA-55x5-fj6c-h6m8 x_refsource_CONFIRM
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https://www.oracle.com/security-alerts/cpujul2022.html x_refsource_MISC
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https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISC
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Mailing List Discussions for CVE-2021-43818 (5)
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https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZQ4SPKJX3RRJK4UWA6FXCRHD2TVRQI44/ vendor-advisory x_refsource_FEDORA
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https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V2XMOM5PFT6U5AAXY6EFNT5JZCKKHK2V/ vendor-advisory x_refsource_FEDORA
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https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WZGNET2A4WGLSUXLBFYKNC5PXHQMI3I7/ vendor-advisory x_refsource_FEDORA
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https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TUIS2KE3HZ2AAQKXFLTJFZPP2IFHJTC7/ vendor-advisory x_refsource_FEDORA
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V. Comments for CVE-2021-43818
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