PoC Exploit Releases for CVE-2023-52447: A Linux Kernel Flaw Enabling Container Escape
Researchers have recently published technical details and a proof-of-concept (PoC) exploit for a significant vulnerability in the Linux kernel, identified as CVE-2023-52447. This use-after-free vulnerability, which has a CVSS score of 7.8, affects Linux kernel versions from v5.8 to v6.6 and poses serious risks for systems using containerization for security isolation. The flaw exists in the Linux kernel’s BPF subsystem due to improper reference counting in BPF programs, specifically involving arraymap pointers. Exploiting this vulnerability requires orchestrating a race condition between two threads, allowing a malicious actor to achieve container escape. The PoC exploit is available on GitHub, providing valuable insights for security teams but also increasing the urgency for patching. The vulnerability has been addressed in a recent kernel patch, and organizations are strongly advised to update to the latest kernel versions that include this fix.
The attack on CVE-2023-52447 begins with the exploitation of a use-after-free vulnerability in the Linux kernel's BPF subsystem, which is leveraged to orchestrate a race condition between two threads. This allows the attacker to modify kernel data structures, such as 'core_pattern', to achieve container escape. BlueRock's Core Pattern String Protection effectively mitigates this step by safeguarding the 'core_pattern' data structure from unauthorized modifications, thereby preventing the attacker from altering it to escape the container environment. This mechanism ensures that even if the vulnerability is exploited, the critical kernel data structures remain protected, maintaining the integrity of the container isolation.
- T1068: Exploitation for Privilege Escalation: The article describes a use-after-free vulnerability in the Linux kernel’s BPF subsystem, which can be exploited by orchestrating a race condition between two threads. This falls under the category of 'Exploitation for Privilege Escalation' as the attacker leverages the vulnerability to escape container isolation.
- T1190: Exploit Public-Facing Application: The article mentions that the PoC exploit is available on GitHub, which implies that the attackers could potentially use publicly available exploit code to achieve their objectives. This aligns with 'Exploit Public-Facing Application' where the attacker uses an existing exploit.
- T1611: Escape to Host: The vulnerability allows an attacker to modify kernel data structures, such as 'core_pattern', to achieve container escape. This involves manipulating the underlying system to gain higher privileges or escape restricted environments, which fits 'Escape to Host' technique.
