CVE-2021-33909 PoC — Linux kernel 输入验证错误漏洞

Source

https://github.com/baerwolf/cve-2021-33909

Associated Vulnerability

Title: Linux kernel 输入验证错误漏洞 (CVE-2021-33909)
Description:fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.

Description

This module fixes an issue in the kernels filesystem layer (CVE-2021-33909) by kprobe-replacing vulnerable functions during runtime

Readme

Kernel runtime fix of CVE-2021-33909
====================================

This repository builds an out-of-tree module named "cve-2021-33909.ko".
cve-2021-33909 fixes an issue in the kernels filesystem layer by kprobe-replacing vulnerable functions during runtime.

It can be build via "make", setting KDIR to the kernels (source-/header-)directory.

It can be loaded directly via "insmod cve-2021-33909.ko",
or copied (+depmod) into the kernels module directory (extra/) and then modprobed with "modprobe cve-2021-33909".

by Stephan Baerwolf, Erfurt 2021

File Snapshot

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