Nice day, everyone. Long time no see. Because I have to do some “great jobs”, so I have disappeared for few months.
In this life, I think everyone really want to control other systems. Today, I will show you one of the best way to do it. This way related to some local exploitation techniques.
We could use them after a successful remote hacking to other systems then escalate privileges. Then we from a normal user to those of a super user (like a SYSTEM or root user) or even to kernel level. These techniques can go by some ways:
Memory corruptions—This refers to a memory corruption in a local service running with high privileges. It is depending on the actual vulnerability and the exploitation mitigations offered by the compiler and the operating system. This is the most dangerous problem because it is usually results in a full-system compromise.
Bad permissions—This type of vulnerability occurs in a local service and is caused by incorrectly setting the privileges or access control lists (ACLs) to objects. For example, a SYSTEM process with a null ACL is easy to exploit, usually with 100-percent reliability.
Logical vulnerabilities – They are great but it is the hardest part. If it is a design-time flaw that allows hacker to takeover of a privileged resource, it is hard to fix with the vendos, because they may require making significant changes in the product. The bug could be deeply integrated and interwoven with other components in the product, making it hard to fix the bug without exposing another bugs.
I’m going to list some “general situations” that I used to do to make a local exploitation.
– Finding hidden features of some products.
– Finding Invalid Privileges, Permissions, and ACLs.
– We have anything in Kernel mode ?
In the first part, we focus on finding hidden features of some products
Finding hidden features of some products
In victim computers, they usually installed a lot of product even some products that they don’t remember or not intentionally.
For ordinary users, the senario leaves them with a huge problem. First, if one of these prodect installed by a hacker, they are done. Nothing to say much.
However, for a knowledge user, they often install a little a number of software but they often have an antivirus, right? So what happens if their Antivirus has a vulnerability that hacker could use it to attack their customers ?
This senario is not a joke. Because these software like Antivirus that often have some hidden features that users don’t know the first thing about it. These features helped their company that will have the way to fix their customers’s computer if there is something wrong in their softwares. For example: writing logs, create files, delete files, ….
So what if hacker abuses these hidden features to do his tasks ? We have many lessons here.
- AVG Antivirus CVE-2017-9977
Code injection vulnerability in AVG Ultimate 17.1 (and earlier), AVG Internet Security 17.1 (and earlier), and AVG AntiVirus FREE 17.1 (and earlier) allows a local attacker to bypass a self-protection mechanism, inject arbitrary code, and take full control of any AVG process via a “DoubleAgent” attack. One perspective on this issue is that
(1) these products do not use the Protected Processes feature, and therefore an attacker can enter an arbitrary Application Verifier Provider DLL under Image File Execution Options in the registry;
(2) the self-protection mechanism is intended to block all local processes (regardless of privileges) from modifying Image File Execution Options for these products; and
(3) this mechanism can be bypassed by an attacker who temporarily renames Image File Execution Options during the attack.
Publish Date : 2017-07-12
Last Update Date : 2017-07-24
Avast Antivirus CVE-2017-8308
In Avast Antivirus before v17, an unprivileged user (and thus malware or a virus) can mark an arbitrary process as Trusted from the perspective of the Avast product. This bypasses the Self-Defense feature of the product, opening a door to subsequent attack on many of its components. Publish Date : 2017-04-27
Last Update Date : 2017-05-09
Avira CVE 2016-10402
Avira Antivirus engine versions before 18.104.22.168 allow remote code execution as NT AUTHORITY\SYSTEM via a section header with a very large relative virtual address in a PE file, causing an integer overflow and heap-based buffer underflow.
Publish Date : 2017-07-27
Last Update Date : 2017-08-23
So let check the softwares on your computers and tell me your results now. Hope we could have some 0-day vulnerabilities here.
In the next part, I’m going to focus on finding Invalid Privileges, Permissions, and ACLs in our system.
Thank for reading, you guys.