Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2021-39220— Bypass of image blocking in Nextcloud Mail

Quick assessment

Affected
nextcloud security-advisories
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.

Nextcloud是德国Nextcloud公司的一套开源的自托管文件同步和共享的通信应用平台。 Nextcloud存在安全漏洞，该漏洞源于网络系统或产品的代码开发过程中存在设计或实现不当的问题。

CVSS 3.5 · Low EPSS 0.78% · P55

Possible ATT&CK Techniques 1 AI

T1059 · Command and Scripting Interpreter
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2021-39220

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Bypass of image blocking in Nextcloud Mail
Source: CVE Program / CVE List V5
Vulnerability Description
Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended that the Nextcloud Mail application is upgraded to 1.10.4 or 1.11.0. There are no known workarounds aside from upgrading.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
输入验证不恰当
Source: CVE Program / CVE List V5
Vulnerability Title
Nextcloud 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Nextcloud是德国Nextcloud公司的一套开源的自托管文件同步和共享的通信应用平台。 Nextcloud存在安全漏洞，该漏洞源于网络系统或产品的代码开发过程中存在设计或实现不当的问题。
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

Vendor Product Affected Versions CPE Subscribe
nextcloud security-advisories < 1.10.4, < 1.11.0 -

II. Public POCs for CVE-2021-39220

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2021-39220

请登录查看更多情报信息。

Patches & Fixes for CVE-2021-39220 (1)

Vendor Advisories for CVE-2021-39220 (1)

Other References for CVE-2021-39220 (1)

Same Patch Batch · nextcloud · 2021-10-25 · 8 CVEs total

CVE-2021-41178 8.8 HIGH File Traversal affecting SVG files on Nextcloud Server
CVE-2021-39225 8.1 HIGH Missing permission check on Deck API
CVE-2021-41177 8.1 HIGH Rate-limits not working on instances without configured memory cache backend
CVE-2021-41179 6.5 MEDIUM Two-Factor Authentication not enforced for pages marked as public
CVE-2021-39221 6.4 MEDIUM XSS in Contacts
CVE-2021-39223 4.8 MEDIUM File path disclosure of shared files in Richdocuments application
CVE-2021-39224 3.5 LOW File path disclosure of shared files in OfficeOnline application

IV. Related Vulnerabilities

Same product: security-advisories
Same vendor: nextcloud
Same weakness: CWE-20

V. Comments for CVE-2021-39220

No comments yet

Leave a comment