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

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2021-3656

Quick assessment

Affected
n/a KVM
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

KVM是基于内核的虚拟机。 KVM 的 AMD 代码中存在安全漏洞，该漏洞源于在处理 L1 来宾提供的 VMCB（虚拟机控制块）以生成/处理嵌套来宾 (L2) 时对“virt_ext”的不正确验证。

AI Predicted 8.2 Difficulty: Moderate EPSS 0.66% · P50
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2021-3656

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
N/A
Source: CVE Program / CVE List V5
Vulnerability Description
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
授权机制缺失
Source: CVE Program / CVE List V5
Vulnerability Title
KVM 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
KVM是基于内核的虚拟机。 KVM 的 AMD 代码中存在安全漏洞，该漏洞源于在处理 L1 来宾提供的 VMCB（虚拟机控制块）以生成/处理嵌套来宾 (L2) 时对“virt_ext”的不正确验证。
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
- KVM Fixed-In v5.14-rc7 and above -

II. Public POCs for CVE-2021-3656

# POC Description Source Link Shenlong Link
1 None https://github.com/rami08448/CVE-2021-3656-Demo POC Details
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2021-3656

请登录查看更多情报信息。

Patches & Fixes for CVE-2021-3656 (2)

Vendor Advisories for CVE-2021-3656 (1)

Mailing List Discussions for CVE-2021-3656 (1)

Same Patch Batch · n/a · 2022-03-04 · 45 CVEs total

CVE-2022-23915 7.2 HIGH Remote Code Execution (RCE)
CVE-2022-26484 4.9 MEDIUM Veritas InfoScale Operations Manager路径遍历漏洞
CVE-2022-26483 4.8 MEDIUM Veritas Infoscale Operations Manager 跨站脚本漏洞
CVE-2022-22946 Vmware VMware Spring Cloud Gateway 信任管理问题漏洞
CVE-2022-26318 WatchGuard Firebox 安全漏洞
CVE-2021-27757 HCL BigFix Insights 安全漏洞
CVE-2021-27756 HCL BigFix Compliance 加密问题漏洞
CVE-2021-44827 Tp-link Archer C2 操作系统命令注入漏洞
CVE-2021-40846 Rhinode Trading Paints 安全漏洞
CVE-2021-46384 MingSoft MCMS 访问控制错误漏洞
CVE-2021-46353 D-Link Dir-X1860 安全漏洞
CVE-2022-23232 Netapp StorageGRID 授权问题漏洞
CVE-2021-3575 OpenJPEG 缓冲区错误漏洞
CVE-2021-3428 Linux kernel 输入验证错误漏洞
CVE-2021-20319 coreos-installer 数据伪造问题漏洞
CVE-2022-21828 Incapptic Connect 安全漏洞
CVE-2022-25623 Symantec Management Center 安全漏洞
CVE-2021-3744 Linux kernel 安全漏洞
CVE-2021-3743 Linux kernel 缓冲区错误漏洞
CVE-2022-23729 LG mobile 授权问题漏洞

Showing top 20 of 45 CVEs. View all on vendor page → →

IV. Related Vulnerabilities

Same product: KVM
Same vendor: n/a
Same weakness: CWE-862

V. Comments for CVE-2021-3656

No comments yet

Leave a comment