CVE-2022-25265: Exec-All Attribute in Certain Binary Files Allows Execution of Bytes in Non-Executable Regions in Linux Kernel

In this article, we discuss a crucial vulnerability found in the Linux kernel, identified as CVE-2022-25265, which has the potential to execute unintended bytes in non-executable regions, specifically in certain binary files. This vulnerability affects Linux kernel versions through 5.16.10.

Background

CVE-2022-25265 pertains to the exec-all attribute, which is a feature found in certain binary files that were built around 2003 (for example, with GCC 3.2.2 and Linux kernel 2.4.20). The exec-all attribute enables the execution of bytes residing in non-executable regions of a binary file. This, in turn, may lead to potential unauthorized execution of arbitrary code, resulting in the compromise of the system's security.

Exploit Details

The primary concern with this vulnerability is the execution of bytes that are not meant to be executed. When a binary file possesses the exec-all attribute, it does not strictly enforce the separation between executable and non-executable regions. Attackers who successfully exploit this vulnerability may potentially elevate their privileges to execute arbitrary code.

Below is a code snippet demonstrating how the exec-all attribute can be applied to a binary file

int main() {
     // Execute a vulnerable binary with the exec-all attribute.
     execv("/path/to/vulnerable_binary", NULL);
}

Upon execution of the vulnerable binary, an attacker could take advantage of the exec-all attribute to infiltrate the host system and execute malicious code.

Mitigation

To safeguard against this vulnerability, it is essential to identify and review binary files that possess the exec-all attribute. It is recommended that users update their Linux kernel to version 5.16.10 or newer. Additionally, the system administrators should restrict access to binary files with the exec-all attribute or rebuild such files to ensure no unnecessary risks are taken.

For more information about this vulnerability, you can refer to the following references

- CVE-2022-25265 - National Vulnerability Database
- Linux Kernel Official Site
- GCC Home Page

Conclusion

CVE-2022-25265 is a high-impact vulnerability that can grant unauthorized users the ability to execute arbitrary code within a Linux-based system. By identifying and updating binary files with the exec-all attribute, users and administrators can minimize the risk associated with this vulnerability. Patching the Linux kernel to version 5.16.10 or newer mitigates the possible exploitation of this vulnerability.

Timeline

Published on: 02/16/2022 21:15:00 UTC
Last modified on: 05/11/2022 14:08:00 UTC