Questions tagged [kernel]
The kernel tag has no usage guidance.
135
questions
2
votes
1
answer
41
views
Linux BPFtrace - user switch from suid bit applications not detected
I want to monitor systemcalls with bpftrace (https://github.com/iovisor/bpftrace/). For most systemcalls, this works without problems, but I have problems to monitor applications, where the suid bit ...
1
vote
1
answer
80
views
user namespaces: do they increase security, or introduce new attack surface?
user namespaces in Linux are presented as a security feature, which should increase security. But is this really true?
Is it possible that while user namespaces fix one kind of problem, they introduce ...
0
votes
0
answers
22
views
Can I know kernel address layout and memory mapped IO layout from the user privilege in linux kernel?
My current understanding is that the user does not have any way of knowing the kernel address space layout due to the protection mechanisms such as Kernel Address Space Layout Randomization (KASLR).
...
0
votes
1
answer
54
views
Why does this method of modifying kernel memory work?
I have no experience of kernel programming or anything low level. I just watched this video and at 21:10 the presenter started to talk about modifying kernel memory using two pointers.
From my ...
0
votes
0
answers
38
views
fscrypt master key handling at kernel space adding additional secure params
In fscrypt, the master key is generated from userspace and actual encryption keys are derived from this master key using KDF.
If any other process is able to get hold of the master key, they can ...
2
votes
1
answer
627
views
Explanation of capabilities: CAP_NET_BIND_SERVICE
I am still studying kernel credential management (https://kernel.org/doc/html/v5.9/security/credentials.html) and I have encountered a use case I cannot explain.
I am in a VM (Kali).
❯ uname -a
...
0
votes
1
answer
39
views
Capabilities DROP in container of Kubernetes pod running with specific UID
I am doing some security research on Kubernetes and I found something still mysterious to me, concerning capabilities.
Example of simple pod:
apiVersion: v1
kind: Pod
metadata:
name: my-pod-httpd
...
1
vote
0
answers
104
views
Was the kernel I used vulnerable/deprecated?
Background Information
As I developer I am running multiple (partly virtual-)machines with Debian GNU/Linux and on some of these machines I work with highly confidential documents or dangerous ...
0
votes
0
answers
24
views
Is it possible to monitor COM class/interface by using ETW
I would like to monitor some COM object/interfaces to identify if a program is using them.
I only managed to monitor the associated DLL loading (with Microsoft-Windows-Kernel-Process) but I can't go ...
0
votes
1
answer
364
views
Is there a difference between a bootkit and a ring-0 rootkit?
I understand the difference between a Ring-0 rootkit and a Ring-3 rootkit, in terms of their hierarchical depth in computational models. That is kernel mode and usermode, respectively.
I am confused ...
0
votes
0
answers
218
views
A Continuous Flood of Kernel Warnings. Am I under attack?
I have a Linksys WRT1200AC with DD-WRT v3.0-r48865 std. It's connected to the Internet through the ISP's modem in bridge mode.
My syslog reports continuously, many times per second stuff like this:
...
2
votes
1
answer
234
views
Container escape - CVE-2022-0492 - hybrid cgroups?
I saw the recent CVE-2022-0492 that can enable container escape, and I have a decent understanding of cgroups and container capabilities, but not very familiar with how hybrid cgroup v1/v2 works, nor ...
2
votes
1
answer
79
views
Security of a ro volume in Docker
What are the security implications of mapping a host folder to a Docker container ro? For example -v /usr/local/bin:/usr/local/bin:ro.
Of course, the container can now read the host folder. But, ...
1
vote
1
answer
140
views
How does gVisor run its own kernel replacement under Docker for security? [closed]
I learned about gVisor from https://security.stackexchange.com/a/259275/133925 . It runs containers under a custom kernel, written in Go, with very intense security.
My question is: The whole point ...
0
votes
0
answers
82
views
How to execute Android verified boot during first boot after updating OS in Android?
I need to execute AVB (Android verified boot) during first boot after updating Android OS. BOARD_AVB_ENABLE = true is already present in the mk file device/hikey/common/BoardConfigCommon.mk in the ...
0
votes
2
answers
356
views
How to completely restrict Steam in Linux to defend against remote zero day exploits?
My question is, how can i completely restrict Steam's processes and modules to only have access to what they suppose to, and not be able to do anything malicious, for example running bin/sh or ...
1
vote
1
answer
200
views
What physical damage can a user mode windows driver do?
If a driver runs in kernel mode it obviously can manipulate everything (well everything in ring 0), so manipulating the file system or devices is a possibility. Potentially devices can be destroyed, ...
1
vote
0
answers
173
views
How to go about checking if Windows is running any untrusted drivers (programatically)
I want to enforce a rule that my program start only if, at the time it launches, there are no untrusted kernel drivers running. I'm aware and have already tested file signature verification using ...
1
vote
1
answer
263
views
Is Zircon kernel (from Fuchsia OS) safer by being a microkernel?
Fuchsia's possible Android replacement uses the Zircon microkernel. This means that the drivers should run in userspace.
Is this an advantage over Android? For example, closed source drivers now can't ...
9
votes
2
answers
615
views
How effective is Windows KDP for exploit mitigation in practice?
Windows Kernel Data Protection is a kernel security feature which appears to use Extended Page Tables (EPT, a hardware virtualization feature) to enforce read-only pages. How effective is this at ...
0
votes
1
answer
137
views
How to detect fileless kernel compromise in linux
Is there a way to detect fileless kernel compromise in Linux?
The only one way to analyze this kind of attack is by volatility. Volatility is a very good product, but not often updated especially with ...
1
vote
0
answers
163
views
ctf kernel challenges does not work [closed]
I'm trying to learn and solve some 'kernel related' ctf challenges (reading writups to try to run same environment and achieve root using one of the kernel-pwn technique...).
I'm using Ubuntu 20 VM ...
1
vote
0
answers
75
views
Can XIP (execute in place) be used for kernel protection?
Starting with kernel 5.13 RiscV will get XIP where parts of the kernel run from non volatile memory like flash. In theory you could make parts of the kernel really read only either from the hardware ...
0
votes
1
answer
99
views
Vulnerability in which part of the Android architecture would allow an attacker to take control of the hardware [closed]
This question is intended for better understanding of security features of Android architecture.
In particular, I want to know what part of the architecture needs to be secure to prevent an attacker ...
1
vote
0
answers
175
views
Security implications of automatic signing of kernel modules on Debian/Ubuntu (like VirtualBox does)
In the past, to install VirtualBox on Debian/Ubuntu you needed to sign some kernel modules, otherwise it would not work. The process involved creating a key pair, importing the public key as a MOK (...
0
votes
2
answers
375
views
Does a (kernel) exploit always need to use system calls?
It was mentioned in this thread that kernel exploits usually use syscalls to trigger undesired behavior:
How can you detect kernel exploits?
Are there any ways or known examples which do not use ...
1
vote
1
answer
514
views
Vulnerabilities for multiple kernel versions that are installed on a given server
As per Exclude or display vulnerabilities for non-running Linux kernels :
It is possible to have multiple kernels detected on a single Linux
host and Qualys will report all vulnerabilities found on ...
2
votes
2
answers
126
views
Is it possible to determinate which functions a kernel module calls?
Trusting kernel drivers is bad. Is there something we can do to have at least an idea about what it does?
For example, let's suppose an armv8a linux kernel. I'd search for all the syscalls, which ...
2
votes
1
answer
774
views
What are the dangers of a firmware malware in 2021 and is it possible?
I was reading a few articles online about how some firmware can be altered into malware and essentially infect a hardware equipment for its entire life time.
Like almost all SSDs in the industry ...
0
votes
1
answer
268
views
Assigning memory address of shellcode to buffer (for buffer overflow input)
I am attempting to exploit HEVD kernel driver buffer overflow challenge:
https://github.com/hacksysteam/HackSysExtremeVulnerableDriver
However when running the below code my windows 7 machine doesn't ...
0
votes
1
answer
262
views
How to get information about segments of physical memory not described in System.map on linux
When I do in linux root shell cat /boot/System.map-$(uname -r) it returns me segments of memory but there is a big gap around phys_startup_64:
00000000000228c0 D softnet_data
0000000000022a80 d ...
2
votes
1
answer
138
views
Can a host OS be attacked through the network stack?
Forenote: I'm not familiar with how virtualisation works on a low-level (but I'd certainly like to learn) so this question could arise from ignorance.
Example Scenario: One virtualised router is ...
2
votes
1
answer
438
views
Linux security modules (LSM) and reference monitor implementation
as far as my understanding goes, an OS needs to implement some sort of reference monitor, as the entity which grants or denies permissions as an access control decision.
Furthermore, I think the Linux ...
0
votes
1
answer
504
views
How do you adjust offest and kernel stack size from an exploit?
Needless to I say I have no idea how to do this.
I'm performing a pentest and I found an exploit related the box : https://www.exploit-db.com/exploits/44298
In the exploit comments, the author said :
...
0
votes
2
answers
139
views
Logging SSH commands on Linux - is custom kernel the only way?
I've done some research and it looks like that the way linux keeps history is less about security and audit and more about helping the user.
Even after making changes to instantly log the command and ...
0
votes
1
answer
416
views
AES-256 ESSIV in dm-crypt
I am playing around with disk encryption. https://gitlab.com/cryptsetup/cryptsetup/-/wikis/DMCrypt#iv-generators says:
essiv: "encrypted sector|salt initial vector", the sector number is encrypted ...
0
votes
1
answer
826
views
How to build Linux Volatility Profiles With the Compiled Kernel
I'm familiar with creating Linux memory profiles as stated here. However, this is assuming that I have access to the live system which often times is not the case.
I heard there is a way to build the ...
1
vote
0
answers
94
views
Kernel ROP crashes running OS
I was experimenting to see if I can make an ROP chain within the kernel. In the kernel debugging mode, I can make the first jump to an arbitrary gadget address without any problem. But the problem ...
0
votes
1
answer
460
views
What is the best way to restrict /proc fs from malicious users (linux)?
I am trying to make a restriction to procfs like only a certain groups of members can perform read and write actions.
kernel document says we can do that by setting hidepid and gid in /etc/fstab. It ...
0
votes
1
answer
260
views
Vulnerable stored Linux kernel version
I am scanning Linux server which has two kernels versions stored, when I run following command I can see for example this version:
user@host [~]# rpm -q kernel
kernel-3.10.0-327.el7.x86_64
kernel-3....
1
vote
0
answers
112
views
Kernel exploit fails after executing first command
While trying to solve old ctf task (https://blog.frizn.fr/plaidctf-2013/pwn-400-servr) I've encountered a situation which I don't understand.
TLTR
After escalating process privileges my exploit ...
0
votes
2
answers
228
views
Is there a reasoning encrypting a GPL binary where I have to publish the sourcecode?
We're a company selling embedded devices. Our devices use u-boot & Linux, both being GPL and therefore we have to release the sourcecode as used to build our binary.
We're in the process of ...
6
votes
1
answer
1k
views
How to hide Kernel Symbols in Linux Kernel Image? Recompliation?
Why hide kernel symbols?
Quote
Anyone with basic knowledge of kernel exploitation knows how important information gathering is to reliable exploitation. This protection hides the kernel symbols ...
5
votes
1
answer
311
views
Can a non-privileged user modify the file descriptor table of an elevated process?
In Linux, every process holds its own file descriptor table, which keeps references to all opened files and file-like devices. This table is managed by the kernel.
Is it possible that a non-...
2
votes
1
answer
474
views
Is it necessary to understand Linux kernel internals to do binary exploitation? [closed]
I am second-year CS student, I know C, OOP concepts, x86 architecture, reverse engineering basics, TCP/IP stack and OS concepts, also I love Linux OS.
I have just one question:
Is it a mandatory to ...
0
votes
1
answer
141
views
Is exploit different from the kernel level or root?
i'm searching privilage escalation. there is some way if you looking at. i trying exploit in my lab machine like vulnhub.
there is a diagram for understanding differents.
anyway I told you a little. ...
1
vote
1
answer
427
views
Securing IPC between kernel and user-mode application
We are currently developing a security software for Windows. This application consists of a service running in user mode and a driver in kernel mode. These two need to communicate, so that the service ...
0
votes
0
answers
547
views
VDSL modem getting probed?
My ZyXEL VMG8924-B30A VDSL modem recently had these alerts in its log. The WAN IP address of the modem is 10.225.205.128.
There was nothing like this before 1 May. What is this?
2019 -05 -01 T16:05:...
1
vote
1
answer
213
views
Why it is difficult to write an application to protect 100% against keyloggers?
When you press keystrokes, I suppose you can intercept in low level code all applications that listen and record. Why it cannot be designed a software that protects 100% against keyloggers, simply ...
1
vote
1
answer
1k
views
linux kernel exploit shellcode causes segfault
I'm learning how to write kernel exploits and my shellcode keeps seg faulting.
I'm getting the memory address for commit_creds(prepare_kernel_cred(0));
#grep commit_creds /proc/kallsyms
c907eea0 T ...