Questions tagged [capabilities]
A capability is a set of access rights granted to a subject, often transferable. Capabilities are a method for access control.
24
questions
0
votes
0
answers
19
views
ptrace: Permission denied with SYS_PTRACE capability [closed]
I have created a pod whose container has the SYS_PTRACE capability (and the SYS_ADMIN)
When I am attempting to attach to another process,
gdb -p 12345
Attaching to process 12345
ptrace: Permission ...
0
votes
0
answers
15
views
Unable to vew /proc/1/environ despite having SYS_ADMIN capability [closed]
I have created a kubernetes pod. The container has the SYS_ADMIN capability.
I can see all host's processes.
However I can not cat /proc/1/environ.
Why is that?
5
votes
1
answer
1k
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
158
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
1
answer
246
views
How to keep data in eBPF maps secure
I have read that there are some capabilities that are broken out of CAP_SYS_ADMIN specifically CAP_BPF, CAP_NET_ADMIN, CAP_PERFMON etc. I also read that data structures called maps are used to store ...
2
votes
1
answer
279
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
136
views
What additional protection does seccomp provide when compared to capabilites?
From this answer I understand that seccomp-bpf filters the list of syscalls a process can call.
Similarly, the capabilites mechanism will cause a syscall to fail if the caller does not have the ...
4
votes
1
answer
549
views
Privilege escalation writing /etc/passwd but without SUID permission on su
This is not an exercise, there might be no solution.
We are producing a Docker image (based on CentOS) which is designed to be executed by a non-root user.
However, this user has write access to /etc/...
-1
votes
1
answer
580
views
Are IPv4 more intuitively hard to track than IPv6?
I understand that it is easier for a human to intuitively figure out the alleged whereabouts of a machine if that machin's IP address is IPv6, rather than if its IPv4:
For example, since I configured ...
2
votes
0
answers
439
views
attach with gdb after dropping privileges
Under Ubuntu 16.04 LTS, I cannot seem to debug a once-privileged process for love or money as an unprivileged user.
The file is setgid (mode 2755). It forks, and the child:
releases its ...
6
votes
1
answer
715
views
What are the security implications of capabilities in Kubernetes pods?
We have a Kubernetes deployment with an application that need to be on a VPN. We implement this requirement by running openvpn-client in a sidecar container within the pod with elevated capabilities:
...
13
votes
2
answers
4k
views
Difference between linux capabities and seccomp
I know seccomp (secure computing) is a way to restrict a process from making particular system calls.
While linux capabilities provides a way to give privileges to specific user or process.
So if I ...
4
votes
1
answer
858
views
Why do capability-based security systems protect against the confused deputy problem?
According to Wikipedia (https://en.wikipedia.org/wiki/Confused_deputy_problem):
In information security, the confused deputy problem is often cited as
an example of why capability-based security ...
19
votes
2
answers
10k
views
Docker: when to use apparmor vs seccomp vs --cap-drop
Docker seems to support both apparmor and seccomp. Docker also allows to drop capabilities when running a container.
However I couldn't find any documentation or guideline on when to use which ...
1
vote
1
answer
966
views
Use of S/MIME capabilities attribute
If you examine an S/MIME-signed file with
$ openssl cms -in file.sgn -noout -cmsout -print
you see that S/MIME capabilities are also included in the signature:
...
object: S/MIME Capabilities (1.2....
4
votes
1
answer
10k
views
Security implications of using SETCAP CAP_NET_RAW
In order to get around the 'problem' of applications requiring root privileges to run, I'm using:
sudo setcap CAP_NET_ADMIN+ep "$(readlink -f /usr/sbin/app)"
sudo setcap CAP_NET_RAW+ep "$(readlink -f ...
2
votes
2
answers
717
views
Making a file immutable (against kernel exploits)
I'd like to know how to make files completely immutable. "Completely" refers in this case to: immutable while the system is running. I could live with something like physical access where someone e.g ...
4
votes
1
answer
678
views
Are Linux System Capabilities Considered Mandatory Access Controls?
DAC is not mandatory because access permissions are left up to the resource owner's discretion.
Mandatory Access Control (Smack, SELinux, etc) administration can only be accomplished by a process/...
2
votes
1
answer
930
views
What is the difference between claims and capabilities in access control?
I've read about the differences between capabilities and access control lists, but to me capabilities seem similar to claims. Can anyone explain the difference, if there is one?
3
votes
2
answers
3k
views
Do `sudo` and `su` belong to capability-based security?
In Linux, do sudo and su belong to Capability-based security ?
For example, when editing a system file, we usually need sudo or su to temporarily switch to user root. Does this example belong to ...
5
votes
1
answer
852
views
Capability-based security vs protection rings: in what sense are they diametrically opposite?
From https://en.wikipedia.org/wiki/Capability-based_security
Capability-based security is to be contrasted with an approach that uses hierarchical protection domains.
From https://en.wikipedia.org/...
6
votes
2
answers
1k
views
Combining capability-based access control with SAML
I have been looking into various research on identity, PKI and access control trying to boil it down to a simplified methodology for IAM (Identity & Access Management).
One thing which pops up in ...
6
votes
2
answers
3k
views
What are the practical differences between SELinux targeted mode and a capability based OS?
I recently asked a question about the differences between capabilities and mandatory access controls.
Among the answers I got the point was made that systems like SE Linux in targeted mode are not a ...
9
votes
5
answers
3k
views
What is the practical difference between MAC and Capabilities
Both Mandatory Access Controls and Capabilities allow for fine grained privileges to be assigned to applications irrespective or in place of privileges inherited by the running user.
Is there any ...