| Name |
Using Malicious Files |
|
| Likelyhood of attack |
Typical severity |
| High |
Very High |
|
| Summary |
An attack of this type exploits a system's configuration that allows an adversary to either directly access an executable file, for example through shell access; or in a possible worst case allows an adversary to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface. |
| Prerequisites |
System's configuration must allow an attacker to directly access executable files or upload files to execute. This means that any access control system that is supposed to mediate communications between the subject and the object is set incorrectly or assumes a benign environment. |
| Execution Flow |
| Step |
Phase |
Description |
Techniques |
| 1 |
Explore |
[Determine File/Directory Configuration] The adversary looks for misconfigured files or directories on a system that might give executable access to an overly broad group of users. |
- Through shell access to a system, use the command "ls -l" to view permissions for files and directories.
|
| 2 |
Experiment |
[Upload Malicious Files] If the adversary discovers a directory that has executable permissions, they will attempt to upload a malicious file to execute. |
- Upload a malicious file through a misconfigured FTP server.
|
| 3 |
Exploit |
[Execute Malicious File] The adversary either executes the uploaded malicious file, or executes an existing file that has been misconfigured to allow executable access to the adversary. |
|
|
| Solutions | Design: Enforce principle of least privilege Design: Run server interfaces with a non-root account and/or utilize chroot jails or other configuration techniques to constrain privileges even if attacker gains some limited access to commands. Implementation: Perform testing such as pen-testing and vulnerability scanning to identify directories, programs, and interfaces that grant direct access to executables. |
| Related Weaknesses |
|
CWE ID
|
Description
|
| CWE-59 |
Improper Link Resolution Before File Access ('Link Following') |
| CWE-270 |
Privilege Context Switching Error |
| CWE-272 |
Least Privilege Violation |
| CWE-282 |
Improper Ownership Management |
| CWE-285 |
Improper Authorization |
| CWE-693 |
Protection Mechanism Failure |
| CWE-732 |
Incorrect Permission Assignment for Critical Resource |
|
| Related CAPECS |
|
CAPEC ID
|
Description
|
| CAPEC-122 |
An adversary is able to exploit features of the target that should be reserved for privileged users or administrators but are exposed to use by lower or non-privileged accounts. Access to sensitive information and functionality must be controlled to ensure that only authorized users are able to access these resources. |
| CAPEC-233 |
An adversary exploits a weakness enabling them to elevate their privilege and perform an action that they are not supposed to be authorized to perform. |
|
| Taxonomy: ATTACK |
|
Entry ID
|
Entry Name
|
| 1574.005 |
Hijack Execution Flow: Executable Installer File Permissions Weakness |
| 1574.010 |
Hijack Execution Flow: Services File Permissions Weakness |
|